The document provides an overview of the Earth's structure, including its three main layers: the core, mantle, and crust, along with details about plate tectonics, which explains the movement of tectonic plates due to convection currents in the mantle. It also outlines various types of plate boundaries (transform, convergent, divergent), the associated geological phenomena such as earthquakes and volcanoes, and the historical development of theories on continental drift and seafloor spreading. Lastly, it discusses the characteristics of volcanic activity and lava types, illustrating the dynamic nature of Earth's geology.

1. Oral Johnson
CSEC GEOGRAPHY
Prepared by: Oral Johnson

2. Oral Johnson
INTERNAL FORCES
The layers of the Earth
The earth is made up of three main layers: the core, the mantle and the crust. These layers
become denser towards the center of the Earth. Density is the degree of compactness, which
increases with depth as a result of higher temperature and greater pressure.
The crust is the thinnest layer of the Earth. The crust is usually between 10km and 60km thick.
The crust thickness is often referred to as the relative thickness of an apple skin (when compared
to the size of an apple). There are two types of crust, oceanic and continental. Continental crust
is made up of silica (Si) and aluminium (Al) while oceanic crust is made up of silica (Si) and
Magnesium (Ma). Continental crust is called (SIAL) and oceanic crust is called (SIMA).
Oceanic crust is between 6 and 10 km thick. Continental crust can be up to 70km thick. Oceanic
crust is denser than continental crust.

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The mantle is the thickest layer of the Earth at 2,900km thick. It makes up nearly 80% of the
volume of the Earth. The mantle itself is divided into 2 layers, the upper and lower mantles. The
mantle is often described as being semi-solid or molten. Here we have magma that flows slowly
due to the convection currents. The rocks in the upper mantle are cool and brittle enough to
break under stress. Rocks in the lower mantle are hot and soft and flow rather than break.
Differences in behaviour separate the upper from the lower mantle.
The upper most part of the mantle and the entire crust makes up the rigid lithosphere. Below
the lithosphere is a more mobile lower layer called the asthenosphere. At the centre of the earth
is the core. The outer core is made of liquid iron and nickel. Heat from the core powers the
convection currents in the mantle. The inner core is the hottest part of the Earth reaching
temperatures between 4,000-4,700°C, which are as hot as the surface of the sun. It contains the
centre of the earth which is about 6,378km from the surface. It is made of solid iron and nickel
that are under so much pressure they cannot melt.
The crust is very thin compared with the diameter of the Earth as whole. If a guava represented
the earth, the skin of the guava would be about the thickness of the crust. However, the crust is
not a continuous layer like the skin of a guava. Instead it is broken up into a number of large and
small segments known as plates. The word tectonics comes from Greek; it means ‘building’. So
plate tectonics means ‘plate building’.

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History of theories
For most of human history people had no idea that the positions of the continents had slowly
changed over time. However, in 1912, Alfred Wegener published his theory of continental drift.
He said that the continents had slowly drifted apart from one super-continent called Pangaea
which existed 200 million years ago. The evidence for this included:
 The fit of continent- the ‘jigsaw’ effect
 Similar plant (India and Antarctica) and animal (South Africa and Brazil) fossils found in
neighbouring continents now separated by water
 Rocks of similar type and age found at the edges of continents that could have once fitted
together.
The American Harry Hess then suggested that deep convection currents would force molten rock
to well up just under the crust. Eventually the increasing pressure would crack the crust and force
it apart. Research on rocks on the bed of the Atlantic Ocean in the 1960s supported Hess’s ideas.
It became clear that the newest rocks were in the centre of ocean at the underwater mountain
range known as the Mid-Atlantic Ridge, which is made up of volcanic rocks. The age of the
rocks steadily increases with distance from the Mid-Atlantic Ridge.

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In 1965 the Canadian geologist J. Wilson linked the ideas of continental drift and seafloor
spreading. He introduced the idea of moving belts and rigid plates which formed the basis of the
theory of plate tectonics.
Why plates move
Plates move because of what happens in the mantle below. The intense heat coming from the
earth’s core causes the magma in the mantle to move very slowly in giant convection currents.
These movements of magma are in places:
 Upwards towards the crust
 sidewards or horizontal to the crust
 downwards toward the core

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These very powerful convection currents cause the plates of the earth’s crust to move. Where the
movement is upwards plates are forced apart and new crust is formed. Where the movement is
downward plates are brought together and plate material may be destroyed. Plate movement is
usually continuous and it causes no problems on the surface of the earth. However, sometimes
movement can be very sudden, causing earthquakes. Most earthquakes are small and have little
effect on people. However, some are of great magnitude and have terrible consequences.
Global distribution of plate boundaries
There are seven very large or major plates:
 Pacific
 North American
 South American
 Eurasian
 African
 Indo-Australian
 Antarctic
The smaller plates include the Nazca, Cocos, and Caribbean plates

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Plates do not overlap. Where they are brought together by convection currents, once plate is
either is forced down into the mantle and destroyed or they are both pushed upwards to form
mountains. The SIMA which forms oceanic crust is denser than the SIAL of continental crust.
The continental curst is permanent.
In contrast, oceanic crust is always being formed in some places and destroyed in others.
Oceanic crust is therefore younger than continental crust. In Greenland the continental crust is
more than 3500 million years old but oceanic crust is nowhere older than 250 million years. The
formation of new oceanic crust and the destruction of old oceanic crust is in balance as the Earth
is neither shrinking nor expanding in size.
Types of plate boundaries
Transform plate boundaries
Two plates slide last each other at a transform plate margins (also known as conservative plate
boundary). Crust is either formed or destroyed nor there any volcanic activity. However major
earthquakes can occur. Usually the plates slide past each other very slowly without any impact
on the surface. But now and then the plates stick. When this happens huge pressure can build up.
If the pressure is released suddenly an earthquake occurs. The plate margin is therefore
conservative because crystal rocks are neither being destroyed or created.

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This has happened many times along the San Andreas Fault in California. In 1906 San Francisco
earthquake the surface moved by 6 meters. It measured 8.3 on the Richter scale. Over 450
people were killed and almost 30 000 buildings were destroyed.
Convergent plate boundaries
Convergent plate boundaries are also called destructive plate boundaries. This happen when two
plates move towards each other. There are three types of convergence:
 Oceanic-Continental
 Continental-Continental
 Oceanic- Oceanic
Oceanic-continental
When an oceanic and a continental plate collide the denser, oceanic plate subducts beneath
the lighter continental plate. A deep-sea trench or subduction occurs when the oceanic plate
is forced downwards into the mantle.
 The increase in pressure along the plate boundary causes the descending plate to
crack. This can cause large earthquakes.

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 The oceanic crust breaks up and melts to form new magma as it descends to great
depths. This is due to friction and the very high temperatures as it enters the mantle.
 The newly formed magma is lighter than the mantle. Some of it may rise to the
surface along lines of weakness in the continental crust
 If a lot of magma rises upwards volcanoes may be formed.
The same process happens when the two plates are oceanic plates. The difference is that the
older oceanic plate is going to be the denser one. There is still subduction and creation of
magma. However the newly formed magma will rise through an oceanic crust to form volcanic
island arcs (which are volcanic islands in water). The Windwards and Leeward Island are a
good example of an island arc.
The Peru-Chile trench is 8050 metres deep. The deepest in the world is the Mariana trench is the
west Pacific Ocean which is 11 022 meters deep.
Continental- Continental (Collision Zone)
Sometimes two plates of continental crust come together. This is called a collision zone. Because
continental crust cannot sink, the crust is forced upwards to form Fold Mountains. An example is
the formation of the Himalayas Mountains. Here the Indian plate is still moving into the Eurasian

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plate at 5cm a year. At times this movement causes major earthquakes. A long time in the past
the sea of Tethys lay between the two land masses. But as the land masses slowly moved
together the sea was squeezed out. The rock strata on the seabed were folded up to form
mountains. Marine fossils found high in the Himalayas prove that these rocks were formed on
the sea floor. The world’s highest mountains are in the Himalayas.
Divergent plate boundaries
Divergent plate boundaries (also known as constructive plate boundaries) occur when two plates
move away from each other. New crust is formed at the boundary as magma moves up from the
mantle below. When this happens underwater, it is described as sea-floor spreading. This
happens at a number of places around the world, for example along the Mid-Atlantic Ridge. This
huge underwater volcanic mountain range has been formed from magma coming from the mantle
below. The lava has an unusual rounded shape and is called a pillow lava. As it oozes out along
the plate boundary it cools quickly on the ocean bed. In places volcanic cones have built up
along the ridge.
Over time these submarine volcanoes may become large enough to reach the surface. This has
happened in Iceland in the North Atlantic Ocean. The main island of Iceland was formed a long

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time ago but in recent times two new small islands have appeared from below the sea. Surtsey
was formed between 1963 and 1967, and Heimaey in 1973. Other islands along the Mid-
Atlantic Ridge include the Azores, Ascension Island and Tristan da Cunha. Because of sea-floor
spreading the Atlantic Ocean is being widened by 2-5cm a year. Almost three quarters of the
lava that pours out onto the earth’s surface each year is found in mid-oceanic ridges. The other
major mid-oceanic ridges are:
 East Pacific
 Pacific Antarctic
 Atlantic-Indian
 Carlsberg
 Mid-Indian.
Where plates move apart on land, rift valleys are formed. In East Africa the African plate is
splitting to form the Great African Rift Valley. It extends for 4000km from the Red Sea to
Mozambique. Its width varies between 10 and 50 km and its sides are up to 600m above the
floor. This rift valley is possibly the start of the formation of a new ocean as east Africa splits
away from the rest of the continent.

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The table below summarizes the relationship between earthquakes and volcanoes and the
different types of plate boundary. Both can occur at convergent and divergent boundaries.
However, earthquakes and volcanoes are at their most violent at convergent plate boundaries.
Only earthquakes occur at collision zones and transform plate margins.
Earthquakes
Earthquakes result from a slow build- up of pressure along plate boundaries. This occurs where
the plates ‘stick’. If this pressure is suddenly released, a violent jerking movement may occur on
the surface. This is an earthquake. The point below the surface where the pressure is released is
known as the focus. The point directly above the focus on the surface is the epicenter. The
epicenter usually experiences the greatest shock or seismic waves. The vibrations due to seismic
waves cause both vertical and lateral movements. These movements can create faults and cause
partial or total destruction of buildings. The impact of an earthquake generally reduces with

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distance from the epicenter. The energy released by an earthquake, described as the magnitude,
is measured on the 10-point Richter scale. A large earthquake can be preceded by smaller
tremors known as foreshocks and followed by numerous aftershocks. The man earthquake may
last less than a minute but aftershocks can continue for several weeks afterwards. Following the
earthquake in Kobe, Japan in 1995, which was 7.2 on the Richter scale, hundreds of aftershocks
were recorded over a three-week period.

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VOLCANOES
The name of the Roman god of fire, Vulcan, gave rise to the English word ‘volcano’. A volcano
is a vent, or opening in the crust, from which pour molten rock, rock debris, gases and
steam. When magma penetrates the surface it is known as lava.
Most volcanoes are found along convergent and divergent plate boundaries. Here there is molten
rock or magma to supply the volcanoes. There are about 1300 potentially active volcanoes in the
world today. A small number of volcanoes are a long way from plate boundaries. These are
found at hot spots. Here the temperature at the boundary of the mantle and crust is unusually
high, and there are lines of weakness in the crust which the magma can follow to reach the
surface. The Hawaiian Islands, in the middle of the Pacific Ocean, have been formed in this way.
Hot spots can also be found beneath continents; an example is the Yellowstone Basin in the USA
Diagram showing a volcano
Crater: This is the opening at a top of a volcano through which lava, ash and gases emerge.

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Conelet / secondary cone/ parasitic cone: This is a small cone which often forms on the side of
an existing volcano.
Pipe: The tunnel like structure which links the vent at the base of the volcano to the crater at the
top.
Magma chamber: a reservoir of magma within the earth’s crust beneath a volcano.
Vent: This is an opening in the earth’s crust from which molten rock, gases, and rock debris
escape.
Ash cloud- A cloud of ash formed by explosive eruptions.
Stages of a volcano
Volcano usually pass through three stages in their life cycle. Volcanoes are:
 Active when they’re currently erupting or eruptions occur at frequent intervals.
OR
Oregon State University- An active volcano is a volcano that has had at least one eruption
in the past 10,000 years. For e.g. Kick em Jenny north of Grenada
 Dormant when eruptions are infrequent and one has not occurred for some time. They are
called sleeping volcanoes.
OR one that hasn’t erupted in the past 10,000 years, but which is expected to erupt again
 Extinct when it is not expected to erupt again.

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Types of Lava/Magma
There are two basic types of lava: basic and acidic.
Basic/Basaltic Acidic
Low silica content High silica content
Darker color Lighter color
It is often very hot reaching temperatures of
10000
C-12000
C
Often has lower temperatures (8000
C-
10000
C)
Rich in Iron and Magnesium Low in Iron and Magnesium
Low viscosity (very fluid and runny e.g. water High viscosity ( very thick e.g. molasses or
toothpaste)
Flows over long distance before solidifying Flows for a short distance then solidifies
Forms gentle sided cones or volcanoes e.g.
shield volcanoes
Forms high, steep and dumpy cones
Eruptions are frequent and gentle Eruptions are infrequent and very explosive
Lava and steam eruptions Ash, rock, gases and lava ejected, pyroclastic
flow likely
It is associated with divergent plate margins
and hot spot volcanoes
It is associated with convergent plate
boundaries ( subduction zones and island
arcs)
Formation of volcanoes
Sometimes magma reaches the earth’s surface through a vent or a fissure (elongated crack).
When magma emerges on the surface it is called lave. If lava emerges through a vent it builds a
cone shape mound (typical volcano we are associated with). Successive eruptions overtime will
build up the cone. If magma emerges through a fissure, it builds up a lava plateau.
A volcanic cone is made of either lava, or a mixture of lava and ash, or ash and cinders only
(small fragments of lava). There are three types of volcanic cone:
 Lava cone ( basic and acidic) – (ONLY LAVA)

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 Composite cone ( both lava and ash)
 Ash and Cinder Cone (ash alone)
Lava cones
Basic lava cones
Some volcanoes erupt a type of lava which flows very easily and tends to flow quite some
distance before solidifying. This is known as basic lava. This volcano is composed of basic lava
which spreads over a wide area before solidifying. This type of lava tends to form broad
volcanoes with very gentle slopes. An example is Mauna Loa on Hawaii. Since these volcanoes
resemble a warrior’s shield, they are called shield volcanoes.
Acidic Lava
This lava cone is made up entirely of acidic lava. Because the lava has a high viscosity it flows
for a short distance then solidifies. Acidic lava produces steep sided and dumpy cones.

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Ash and Cinder Cone
In a violent volcanic eruption lava can be thrown to great heights where it cools and breaks into
small fragments of lava known as volcanic ash/cinders. The ash falls to the surface building up a
cone. Successive eruptions will build the cone overtime. An example is Paracutin in Mexico

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Composite cones/Stratovolcanoes
Some volcanoes produce different types of eruptions. Sometimes there are massive ash eruptions
which produces layers of ash. At other times there are eruptions of lava which produces layers of
lava. The ash is the result of a violent eruption while the lava is produced by more gently
eruption. The result of a series of eruptions is a steep sided cone composed of successive layers
of ash and lava. This type of volcano is known as a composite cone. Composite cones are found
near convergent plate boundaries. The Soufriere Hills volcano in Montserrat is an example of a
composite cone.

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Extrusive volcanic features
When lava cools and solidifies on the earth’s surface it forms extrusive volcanic features.
Examples include ash and cinder cone, basic lava cone, acidic lava cone, composite cone caldera,
spine, lava plateau and spine. These are all landforms are features above the earth’s surface.
Caldera
A volcanic eruption may be so explosive that the whole top of the volcano sinks into the magma
below. A huge crater is left which may by many kilometers in diameter. Later eruptions may
form new cones inside a caldera. Lakes may form in the lowest parts of a caldera. An example is

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Krakatoa in Indonesia. The Qualibou caldera in St. Lucia is 3.5 km x 5 km in size and was
formed more than 30,000 years ago. The town of Soufriere is located inside of it.

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Lava plateau/ Basalt plateau
Lava does not always reach the surface in a spectacular way. Sometimes large quantities of lava ooze out
slowly onto the surface from fissures (surface cracks). These fissure eruptions can cause lava to spread
out over a very wide area. Over time, a number of fissure eruptions in the same area can build up a high
plateau. Basalt plateaux are very large features, covering hundreds of thousands of square
kilometers and they usually “drown” the pre-existing landscape. In India the Deccan is a lava
plateau which covers almost 650 000 km2
Volcanic Spine
Sometimes acidic lava is so viscous that it cools and solidifies in the crater to form a spine or plug.
However spines are rare because they often break up rapidly on cooling.

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Intrusive volcanic features
Only a small amount of the magma that moves up from the mantle and through the crust reaches the
surface. Most magma cools and solidifies (hardens) before it reaches the surface. As the magma moves
upwards it forces its way into lines of weakness in the rock. Bedding planes, joints and faults are all lines
of weakness followed by the magma. Once magma gets into a crack in the crust the huge force behind it
can cause the crack to widen.
Although intrusive volcanic features are formed underground, they may be exposed millions of years later
if the rocks at the surface are eroded. Because volcanic rocks are hard they are often more resistant to
erosion than the rocks around them and they stand out in the landscape as higher ground.
 A dyke is formed when magma moving upwards towards the surface cool and solidifies. The
magma cuts across the bedding planes of sedimentary rock. Sometimes a large number of dykes,
called a dyke swarm, can occur together in an area. An example is the Moule a Chique headland
found at the southern tip of St Lucia.
 A sill is formed when magma flows horizontally between rock layers, roughly parallel to
the surface. This molten material cools forming a horizontal sheet of solid rock called a
sill. This may be horizontal or angled towards the surface.

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 A laccolith is the result of large amounts of magma moving between rock layers causing
overlying rock strata to arch upwards.
 A bathlolith is much larger than the other intrusive volcanic features. It forms when a
giant underground reservoir of magma cools and hardens to form granite. Batholiths can
be several hundred kilometers in diameter. A batholith may form the roots of a mountain.
A good example in the Caribbean is the Tobago Batholith

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Positive and negative effects of volcanic activity
Positive effects
Fertile Soils
Volcanic materials produce fertile soils. Ash and cinder are natural fertilizers as they are rich in
minerals. As lava cools and is eroded by the elements it also adds to soil fertility. For this reason
agriculture often thrives in volcanic regions, e.g. near Mt Vesuvius, which is an important
vegetable production are in southern Italy.
Land surface
Erupting volcanoes are thought to be the source of the first land as the hot planet cooled.
Eruptions continue in the sea creating new land. All the volcanic islands are created in this way.
There are so many islands that were created as a result of volcanic activity. The Eastern
Caribbean islands, the Aleutian Islands and the Marianas islands in the pacific are all volcanic
island arcs and were formed as a result of volcanic activity
Minerals
Many useful materials are formed directly or indirectly from volcanic activity. Building
materials such as granite and marble, precious minerals such as diamonds as well as silver and
copper are formed from magma and in and on the earth’s crust. Other mineral resources such as
gold, silver, nickel, copper, and lead are sometimes found around volcanic activity.
Geothermal energy
Geothermal energy production in Iceland is another positive of volcanic activity. Iceland is on
the Mid-Atlantic ridge (plates separating) and for this reason has a lot of volcanic activity.
Magma rises close to the surface of the crust and this heats the groundwater. This water is heated
to well beyond boiling point (up to 200 degrees Celsius) and becomes “super-heated”. Wells are
drilled into the rock and the hot water is pumped out. As this hot water reaches the surface it
does so as steam due to the intense heat. This steam is then used to drive turbines and create
electricity

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Tourism
Volcanic peaks. Whether active or formant are natural tourist attractions in many parts of the
world. From the majestic Mt Fuji in Japan to the ever flowing Hawaiian cones, tourist visit and
wonder at this evidence of the earth’s interior. Volcanoes are also important tourist attractions.
Mount Vesuvius in Naples and Mount Etna in Sicily are major tourist attractions in southern
Italy. In Iceland, the geysers and hot springs caused by volcanic activity bring many tourists to
the island. This tourism generates jobs and money in areas that may not have many other sources
of employment. Jobs are generated in areas such as accommodation, transportation, sight-seeing
and retail (shops).Geysers are also used as tourist attractions such as the Yellowstone National
Park.
Building Construction
When lava/magma is cooled it form igneous rocks. Some igneous rocks such as granite are being
used in the construction industry for thousands of years. Granite is very durable and strong
igneous rocks that is used for all kinds of structures. Because pumice is so light it is used quite
often as a decorative landscape stone. Basalt is also quarried in some part of the world and is
also widely used in the construction industry.
Negative Effects
Poisonous gases - Although the predominant gas erupted from volcanoes is H2O vapour, other
gases are erupted can have disastrous effects on life. Some of these gases are hydrogen sulfide
(H2S), sulphur dioxide (SO2), hydrogen fluoride (HF), carbon dioxide (CO2), and hydrogen
chloride ( HCL). Gases such as carbon dioxide, carbon monoxide, and sulfur dioxide can travel
down a volcano and asphyxiate (suffocating) wildlife and humans.
Lava flows
A river of molten rock 1000 degrees centigrade that can travel at 40mph. lava flows
can cause extensive damage or total destruction by burning, crushing, or burying everything in
their paths. Lava flows can erupt relatively non-explosively and move very slowly (a few meters
to a few hundred meters per hour) or they can move rapidly (typically down steep slopes.

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Tephra
All materials ejected from a volcano are called Tephra. These occurs when there is an
explosive eruption. They are classified according to their sizes. Materials the sizes of a football
can be ejected from a volcano. Ash, lapilli and volcanic bombs are tephra. The largest pieces of
tephra (greater than 64 mm) are called blocks and bombs often fall close to the volcano but
smaller size tephra such as ash and lapilli ( lapilli 2-64 mm) and ash (<2 mm) can be carried
downwind and affect areas far from the volcano. Millions of tons of ash can bury buildings.
Problems associated with tephra
 If ash builds up on the tops of roofs, it will often cause collapse. This is especially
common on flat topped buildings. Most deaths resulting from the eruption of Mount
Pinatubo in 1991 were due to collapsing roofs (Wolfe, 1992).
 Ash can disrupt electricity, television, radio, and telephone communication lines, bury
roads and other manmade structures, damage machinery, start fires, and clog drainage
and sewage systems
 Ash is also a great hazard to airplanes. Ash from the 1982 eruption of Galunggung
Volcano in West Java, Indonesia caused engines in two jet airplanes to fail. Both aircraft
dropped 25,000 feet before they could get their engines to start again.
 Tephra can also destroy vegetation which can result in famine. Famines are the largest
indirect hazard produced by volcanic eruptions. In 1815, after the eruption of Tambora
which ejected 151 cubic kilometers of ash into the atmosphere, 80,000 people died due to
famine (Bryant, 1991 and Francis, 1993)
 Ash can produce poor visibility and cause respiratory problems.
Pyroclastic flows
Pyroclastic flows are very hot, fast moving clouds of gases and

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tephra moving down the side of a volcano after an eruption column collapse. They are
also called nuée ardentes. They are extremely dangerous because they can travel up to
500 km/hr., reach distances of 30km and can be over 700 degrees Celsius in temperature.
They will burn, knock over or bury anything in their path. A pyroclastic flow from
Vesuvius volcano killed about 20,000 people in Pompeii in 79 CE.
Lahars (resembles wet concrete)
A volcanic eruption usually leaves lots of loose unconsolidated fragmental debris. When this
loose material mixes with water from rainfall, melting of snow or ice, or draining of a crater lake,
a mudflow results. Volcanic mudflows are called lahars. These can occur accompanying an
eruption or occur long after an eruption. Lahars are very dangerous because they do not require a
volcanic eruption yet can travel hundreds of miles. All that is required is loose pyroclastic
material on the volcano that mixes with precipitation or melting snow. In general, they destroy
anything in their path, carrying away homes, buildings, bridges, and destroying roads, and killing
livestock and people.

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TYPES OF ROCKS
Rocks
A rock is any hard, naturally occurring substance which is composed of minerals and which is
formed by geological processes. A mineral is a substance which is normally crystalline and is
formed by geological processes. Crystalline means the atoms forming the crystals are arranged in
a definite manner. Some minerals are non-crystalline, i.e. the atoms forming the mineral are not
arranged in any definite order. Most minerals are compounds of several elements, e.g. Silica
(SiO). A few minerals are themselves elements. A geological process is any natural process
which modifies (changes) geological features. People who study rocks have found it useful to
classify them according to the processes by which they were formed. There are three major ways
in which rocks are formed and hence there are three major classes of rock; igneous rocks,
sedimentary rocks and metamorphic rocks.
Igneous Rocks
These rocks are formed when molten rock from deep within the Earth’s crust (magma) finds its
way into or onto the Earth’s crust where it cools and hardens. They do not occur in layers and
most of them are crystalline (contain crystals)
Intrusive igneous rocks
When magma cools and hardens within the Earth’s crust the resulting rocks are called intrusive
igneous rocks. Intrusive igneous rocks are also called plutonic igneous rocks. Because these
rocks were formed by the slow cooling of magma, they often contain large crystals, making them
coarse grained. Examples of intrusive igneous rocks are granite and gabbro. These igneous are
usually made up of large crystals which can be seen with the naked eye. They only reach the
earth surface when the rocks above them are eroded.

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Extrusive igneous rocks
When magma reaches the Earth’s surface it is known as lava. This lava cools and hardens
quickly, forming what are known as extrusive igneous rocks or volcanic igneous rocks. These
rocks are usually fine grained as the lava cools too quickly to allow large crystals to develop.
Basalt and obsidian are examples of extrusive igneous rocks. The crystals are usually so small
that is almost impossible to see with the naked eye. Obsidian (also known as volcanic glass) is
formed when lava cools so quickly that crystals are unable to form.
Sedimentary rock
These rocks are formed when material which has been deposited by agents such as rivers is
compacted over time until it hardens into rock. This usually happens in bodies of water such as
the sea. The material is deposited in layers and these layers are often clearly visible in the
resulting rock. Examples of sedimentary rocks include limestone and sandstone. All sedimentary
rocks are non-crystalline (contains no crystals). However they usually contain fossils. There are
three main groups:
 Mechanically formed or clastic sedimentary rocks- They are made from pieces of other
rocks damaged by weathering and erosion. They form when layers of sediment
containing this debris accumulate and cement together into a sedimentary rock. Examples
include: Breccia, siltstone, conglomerate, sandstone and shale
 Chemical sedimentary rocks are made from tiny particles of minerals that precipitate
from a liquid in which they were originally dissolved. Limestone forms when calcium
precipitates out of water to form a layer of tiny particles that eventually cement together
to form rock. Examples include: rock salt, iron ore, chert, flint, some dolomites and some
limestones

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 Organic sedimentary rocks are form the accumulation of plant and animal remains.
Examples from animal accumulation include chalk and coral. Examples from plants are
peat, lignite and coal
Metamorphic rock
When igneous or sedimentary rocks are subjected to intense pressure and heat over a long period
of time, their structure and mineral composition may change a great deal. These rocks
metamorphose into a completely different type of rock. The heat and pressure required to bring
about this change in the rock exists far below the earth’s surface. Examples of metamorphic
rocks are marble (which is metamorphosed limestone) Examples
-Slate from clay
-Gneiss from granite
-Quartzite from sand
-Graphite from coal

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EXTERNAL FORCES
Weathering
Everywhere in the world rocks are worn away by many different processes. Depending on the
exact location the processes that operate vary because they are affected by climate, rock type
relief and slope angle. For example, rock types are different in hardness (resistance); the more
resistant ones wear away more slowly than softer ones. The hotter and wetter the climate the
faster weathering and erosion happen
Denudation
Denudation simply means the wearing away of the land by weathering and erosion. It includes
all natural agencies, for example sun, rain, frost, wind, rivers, sea, ice, temperature change and
even the actions of plants and animals. This set of major processes is responsible for the creation
of the Earth’s varied landscapes.
Weathering
Weathering is the wearing away (disintegration and decomposition) of rocks by the effects of the
weather and the atmosphere. No movement is involved in this, so the breakdown of the rock is
said to be ‘in situ’- in other words, ‘in that place’. Sometimes, after the break-up of the rock,
fragments are moved but only by gravity, for instance slipping down a slope.
Erosion
Water, ice and wind also wear away the earth’s surface. Water can mean either rivers or the sea.
Ice is in the form of glaciers. Wind erodes especially when it is carrying something to help it
wear away rock, usually sand. (Imagine how a blast of wind carrying sand would feel against
your skin!).
The difference between erosion
The key difference here is movement. In the case of weathering, no movement is involved
(remember the term in situ). The agent that weathers the rock does not move the debris. Any
movement of loose fragments happens due to gravity. However, in erosion, the agent breaking
up the rock also removes the debris. For example, the sea attacks cliffs and moves the fragments

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out to sea or along the beach. A glacier erodes the rock it moves over and carries fragments
within it, depositing them many kilometers away when it melts.
There are three different types of weathering:
 Physical ( or mechanical) weathering
 Chemical weathering
 Biotic ( or biological) weathering
Physical weathering
Physical weathering – This involve rocks breaking apart but without any chemical change taking
place.
Frost shattering/Freeze-Thaw
Globally, frost shattering, or the freeze-thaw process, is the most important and widespread type
of weathering, although it is less common in the Caribbean due to this region’s tropical latitude.
Only the highest areas could be affected. For this type of weathering to occur the temperature
must fluctuate (change or vary) either side of 00C. There must also be bare rock exposed at the
surface, with little vegetation cover to protect the rock from the weather conditions.
If it rains during the day, or there is moisture from dew or melting ice or frost, water can trickle
into cracks, crevices or pores in the rock. Daytime temperatures are more than 00C. If at night
the temperature drops below zero, the water in the cracks or pores freezes. Ice take up 9% more
space than equivalent amount of water and so exerts pressure on the rock. Repeated freeze-thaw
conditions continue throughout the winter in the cool temperate zones of the world, slowly
widening the cracks until pieces of rock break-off. Frost shattering is most likely to happen on
steeper bare rock slopes, so the broken pieces will slip downhill easily under the force of gravity.
They collect at the bottom of the slope in a fan-shaped pile. This is called scree or talus. Where
the land is more level then boulders ad smaller stones litter the surface. These too have been
broken off by frost shattering. They are known as blockfields or felsenmeer.
In colder regions frost shattering is less common, as temperatures are too low; the fluctuation
around 00C does not happen very often. It rarely becomes warm enough, even during the day,
for melting to occur. In Polar Regions it is very unusual for temperatures even to rise above zero.

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Temperature changes
Rocks expand when heated and contract when cooled. Regular heating and cooling occurs in
some climates. In hot deserts the diurnal range of temperature (that is temperature differences
within a 24-hour period) can be as much as 500
C
At midday over 400C is not uncommon, but at night temperatures may drop below freezing
(O0
C). The outside layer of rock therefore expands and contracts regularly. This weakens it until

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eventually it peels off. This process is known as exfoliation or onion peeling. After one layer has
broken off the next one is attacked by temperature change.
Rocks are made up of different minerals such as granite. These minerals can expand and contract
at different rates which causes the rock to disintegrate- a process known as granular
disintegration.
Pressure release
Pressure release also results in exfoliation, but here the cause is different. Rocks deep
underground, such as igneous intrusions for e.g. granite, have the weight of other rocks above
pressing down on them. The granite of Dartmoor in south-west England was formed 6km deep
below the surface, so had a huge mass of rock pressing down on it. Such pressure sets up stresses

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within the lower rock. Over time, the upper rocks are weathered and eroded away, so the
pressure is reduced and the stresses are less. The rock expands as joints and other cracks open
up, almost as if they were breathing a sigh of relief! This widening of cracks is called dilation.
The cracks formed are roughly parallel to the surface, so the layers of rock peel away one at a
time, like the skin of an onion. This is called exfoliation. Pressure release is responsible for
causing large-scale rounded landforms, such as Half Dome in Yosemite National Park, USA. In
the Caribbean, pressure release has been partly responsible for some of the granite landforms on
Tobago.

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Chemical Weathering
Chemical weathering is where a chemical change causes rocks to dissolve or decay.
Carbonation
Carbonation is the most important form of chemical weathering in limestone areas, whether they
are in tropical or temperate zones of the world. Rainwater containing carbon dioxide absorbed
from the atmosphere is able to dissolve calcareous (calcium–based) rocks. Carboniferous
limestone and chalk are the types of limestone affected most because they are made of almost
pure calcium carbonate.
Here are the stages of the process:
1) Rainwater dissolves carbon dioxide from the air as it passes through it
H2O + CO2 = H2 CO3
Rain water + Carbon dioxide = Mild carbonic acid
2) The mildly acidic rainwater reacts chemically with the calcium carbonate in the rock
H2 CO3 + CaCO3 = Ca (HCO3)2
Mildly acidic rainwater + calcium carbonate = Calcium bicarbonate
3) Calcium bicarbonate is soluble in water so it is easily washed away
The higher temperatures in tropical areas increase the speed of carbonation. Chemical reactions
are faster as temperature increases. Higher rainfall also plays a part because the rain is the
weathering agent.
Few minerals are soluble in pure water. It is important to understand than it is the weak acid that
allows this natural process of carbonation to take place. However, the carbon dioxide in
rainwater is not the only source of acid that can attack limestone. Any acid will attack calcium
carbonate, including those coming from industrial pollution. Nitrates and sulphates make nitric

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and sulphuric acids and both of these can dissolve in rainwater too. The carboniferous limestone
of the Pennine Hills in Northern England may have been dissolved faster due to the pollution
from the nearby industrial areas in that part of the country.
The Cockpit country in Jamaica is a world-renowned Limestone area. Features such as cockpits,
cones, stalactites and stalagmites were formed due to carbonation. The high annual rainfall and
high temperatures combine to cause extremely rapid limestone weathering.
Solution
Solution simply means the dissolving of minerals in water. Rocks other than limestone can be
affected by solution weathering. Many minerals are soluble in water, especially if the water is
slightly acidic as explained in carbonation. The greater the acidity (the lower the pH) the more
effective the rainwater will be in dissolving minerals in rocks. Rock salt (halite) is one mineral
that is particularly vulnerable to this process and can be dissolved easily ‘in situ’.
Rocks made up of a mixture of different minerals can be weathered by one or more of them
being dissolved, leaving the rock structure weaker. Other agents of weathering and erosion can
then attack more easily.
Oxidation
Oxygen occurs when rocks are exposed to oxygen in air or water. It is chemical addition of
oxygen to compounds in the rock and it can weaken the structure of the rock. The process of
oxidation has a similar effect on iron minerals within rocks. The chemical changes turn the solid
iron minerals into powdery red or brown clay. This then causes the rock to crumble and break
apart. This weathering process is also known as rusting, and the rock discolours to the reddish-
brown colour seen on rusty metal.
Iron can combine with oxygen to make two different compounds, ferrous iron oxide (FeO) and
ferric iron oxide (Fe2O3). Ferric oxide clearly contains more oxygen per atom of iron than
ferrous oxide.
4FeO + O2 = 2Fe2O3
Ferrous iron oxide + oxygen = Ferric iron oxide

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Evidence of oxidation can be seen in many regions of the world, particularly in hot deserts and in
parts of the tropics where iron-rich rocks are readily weathered in the warm and wet conditions.
Hydrolysis
Hydrolysis is the chemical breakdown of a substance when combined with water. The prefix
‘hydro’ means ‘water’ and the suffix ‘ lysis’ means to ‘break down’. With chemical weathering
of rock, we see a chemical reaction happening between the minerals found in the rock and rain
water.
The most common example of hydrolysis is feldspar, which can be found in granite changing to
kaolinite clay. When it rains, water seeps down into the grounds and comes in contact with
granite rocks. The feldspar crystals within the granite react with the water and are chemically
altered to form clay minerals, which weaken the rock.
Biotic weathering
Biotic weathering refers to the role plants and animals play in breaking down rocks. Plants and
animals can promote both the mechanical and chemical breakdown of rocks.
Biotic (physical)
By plants
Plants can grow anywhere as long as there is water. Plant roots can enter joints or cracks in order
to find moisture and nutrients. As the tree grow the roots become larger. Overtime when the root
size increase it exerts pressure or force on the crack. Overtime the small joint/crack will become
wider and deeper. This will eventually cause the rock to break apart.
You may have observed before tree roots can split into sections or driveways sufficiently to raise
and crack the concrete.
By animals
a) Burrowing animals like rabbits, moles, earthworms and even ants can contribute to biological
weathering. These animals can move rock fragments to the surface. As a result, these fragments
become more exposed to other environmental factors that can further enhance their weathering.

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b) These burrowing animals also create holes which makes an easy passage of water and other
weathering agents deeper into the soil into the ground where it can cause further disintegration of
rocks.
Biotic (chemical)
Animals living on the surface of the rocks on the coast secrete chemicals that dissolve rocks.
Some micro-organisms get nutrients by taking minerals from rocks. By removing these minerals
the rock becomes weaker. An animal called the Piddock shell drill into rocks in order for it to
protect itself. The Piddock shell secrete an acid that helps to dissolve the rock. Overtime the rock
gets weaker due to this process.
Another example is Lichen. Lichen is fungi and algae living together in a symbiotic relationship.
The fungi release chemicals that break down the minerals in the rock. The minerals released
from the rock are consumed by the algae. Over time the rock becomes weaker due to this
process.

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MASS WASTING
Mass wasting (also known as mass movement) refers to the movement of weathered material
downslope because of the influence of gravity. Two of the major form of mass wasting includes
soil creep and landslide
Landslide
A landslide is a sudden movement of rock or soil downslope under the influence of gravity. They
can have devastating consequences on the environment and all who inhabit it. Landslides can
block roads and railways, destroy buildings or even bury entire villages. All slopes are affected
by gravity, so loose material will eventually slip or fall. On gentler slopes, around 5 degrees, soil
creep operates which is so slow that is has relatively little effect on human life, property or
activity. Landslides are natural events and would occur without people, but human activities do
increase the risks, scale and frequency of these hazards.
Physical causes of landslides
Unconsolidated material on the slope
In 1998 the rains from Hurricane Mitch caused devastating mudflows from the unconsolidated
ash slopes of the unconsolidated ash slopes of the Caista volcano which killed 1900 people and
destroyed the town of Posoltega in Nicaragua
On steep slopes
All slopes are affected by gravity, so loose material will eventually slip or fall. The steeper the
slope the likelihood of experiencing a landslide increases. Landslides usually occur on steeper
slopes while soil creep occur on gentler slopes.

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Type of rocks
Shake and clay are both slippery, especially when wet. Wet clay acts as a lubricant so rock beds
above it slip down more easily. Shale is made of several very thin layers, so it slides easily,
taking any rocks above with it
The block of limestone slides on clay as it becomes slippery when wet
Angle of bedding planes
Bedding planes being roughly parallel to the slope surface makes it easy for material to slip
downward along the bedding planes. Gravity can exert its force easily on the rock beds. If the
underlying rock layers are impermeable a rock is more susceptible to slide. This keeps all the
moisture in the top layer of rock so it becomes saturated quickly.
Erosion of the base of a slope by rivers or ocean waves (Basal cutting)
Slopes on a coast are subjected to coastal erosion. Erosion takes place at the base of the slope.
The base provides stability or support. If the slope above is made of unconsolidated or very wet

43. Oral Johnson
material and this becomes unsupported it is much more likely to collapse. When a river valley
erodes it produce a similar effect.
Precipitation
Heavy rains can cause slopes to become saturated which further weakens the slope. When the
material becomes saturated it becomes heavier and friction is reduce. When this happens a
landslide can take place. This is why so many slides occur after heavy and short intense period of
rainfalls especially in the tropics from tropical storms or hurricanes. Water does two things:
 It adds weight to the material, making the slope less stable
 It decreases friction which helps movement downslope
The torrential rain from hurricane Mitch in October 1998 caused flooding and landslides which
affected 3 million people in the Caribbean side of Nicaragua and Honduras. .
Volcanic eruptions
When a volcano erupts it ejects several types of materials. These include materials such as ash,
tephra and bombs. When the ejected material especially ash is mixed with water/ice slurry like
liquid is formed. These are term lahars. Perhaps the best known example is the one that occurred
in Colombia in 1985, when 21 000 of the
22000 population of Armero died following the eruption of the volcano Nevado Del Ruiz.

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Earthquakes
The vibrations from an earthquake can destabilize slopes. The vibrations and shaking can cause
the soil to lose strength and may cause an unstable slope to collapse. Earthquakes of magnitude
4.0 and greater have been known to trigger landslides
In the 1970s a powerful earthquake caused the partial collapse of Huascaran mountain in Peru.
The avalanche of rock and ice, travelling at speeds in excess of 300km/h destroyed the town of
Yungay in the Rio Santa Valley and killed some 20, 000 persons.
Landslides are also influenced by human factors
Building on unstable slopes
It is normal for a human being to build his house on a terrain without knowing the geology. At
times they may build their houses on unstable slopes. The weight of the building adds pressure to
already unstable slope. Over time the increase pressure my result in a landslide.
In December 1999 there were hundreds of landslides in and around Caracas the capital of
Venezuela. These major causes were heavy rain and by the activity of humans. The other two
causes involved human factors: steep sided valleys with unstable slopes had been used for high
rise buildings and vegetation had been removed to make way for these. This disaster left 30000
dead and 200 000 homeless.
Removal of Trees/ Deforestation
Human activities, such as deforestation, can make landslides more likely. In a forest, tree roots
help to bind the soil together. When trees are removed the soil become exposed and there are no
forest trees to hold the soil together. Any intense rainfall can easily saturate the soil making it
heavier and unstable. Deforested slopes are therefore prone to landslides.
Undercutting the base of a slope by road building
When humans undercut the base of a road to facilitate road building the slope is left unsupported,
the materials above it will collapse. It has the same effect as physical erosion.
Dumping waste material

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Waste from activities such as coal mining can be difficult to dispose of. In the village of Aberfan
in South Wales, UK, the material was piled up on the slopes of 25 degrees above the village. A
wet autumn in 1966 saturated the coal tip. The tip collapsed on the morning of 21 October,
engulfing the local junior school, killing 116 children and 5 teachers. This was one of the worst
disasters in the UK in the 20th
century.
Building Dams
One of the worst disasters of the 20th
century in Europe was in the north-east Italy in 1963. The
Vaoiant dam had been built across the narrow, steep-sided Piave valley. The rock beds of
alternate limestone and clay sloped towards the reservoir. The pressure of the weight of water in
the reservoir caused a small earthquake. A block of limestone slipped on the clay beneath, falling
into the water and forcing a 100 meter wave over the dam. Within seven minutes it hit three
small towns including Longarone. The speed of the disaster and the fact it happened at night
caused the high death toll of 3000. This could have been avoided through better planning and
quicker reaction to earlier ground tremors.

46. Oral Johnson
Soil Creep
Soil creep is the slow, gradual movement of soil and rock particles down a slope under the
influence of gravity. This is the slowest of downhill movements and is difficult to measure as it
takes places at a rate of less than 1cm a year. However unlike faster movements, it is an almost
continuous process. Soil creep occurs mainly in humid climates where there is a vegetation
cover. More materials end up at the bottom of a slope by this process than in any other way. It
can take place on gradients as slight as 2 degrees but more usually on those of over 5 degrees.
There are two major causes of creep both resulted from repeated expansion and contraction.
Freeze-thaw when regolith (weathered material) freezes, the presence of ice crystals increases
the volume of the soil by 9 percent. As the soil expands, particles are lifted at right angles to the
slope in a process called heave. Sediments can expand when they freeze get wet or heated up in
the sun. When the ground later thaws and the regolith contracts (shrinks), the particles fall back
vertically under the influence of gravity and so move down slope. Creep takes a long time
because of each particle only move a millimeter to a few centimeters at a time
Wetting and Drying -Wet dry periods during times of heavy rainfall, moisture increases the
volume and weight of the soil, causing expansion and allowing the regolith to move downhill
under gravity. In a subsequent dry period, the soil will dry out and then contract.

47. Oral Johnson
Evidences of soil creep
 There are many indicators that show a soil creep is happening. The clearest one is the
formation of terracettes. These are step like features, often 20-50 cm in height which
develops as the vegetation is stretched and torn.
 Trees also clearly show the effects of soil creep. As they slip gradually down a slope
they try to grow vertically as before, resulting in the bending of the trunk.
 Tilting of utility poles along the slope
 Build up accumulation of soil behind walls built along the slope.
 Walls bulge or break

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Conditions influencing soil creep
1. Climatic environment
In temperate environments soil can creep downhill at between 1 and 2 mm per year, but in
tropical regions it is quicker , perhaps 3-6 mm . In cold semi – arid areas it is even faster.

49. Oral Johnson
RIVERS
THE WATER CYCLE
Over 97% of the world’s water is stored in oceans and seas. These water bodies make up about
70% of the surface of the Earth. The remaining stores of water are:
 2.1% as ice and snow ( most of this is Antarctica and Greenland)
 0.6% as ground water (held in rocks)
 0.1% in rivers and lakes
 0.001% held in the atmosphere as water vapor and clouds (water droplets). This amounts
to about 10 days’ supply of average rainfall around the world. If evaporation and
transpiration from the Earth’s surface suddenly stopped the world would run short of
water very quickly!
The three main processes in the water cycle are evaporation, condensation and precipitation.
 Evaporation is the process in which liquid water is changed into water vapor which
is a gas. Evaporation takes place mainly from surface water. Energy is needed for it to
occur. The energy comes from the sun’s heat and from wind. Look how quickly water
evaporates from concrete or tarmac on a very hot day compared with a cooler day!
Evaporation is also faster on a windy day compared with a calm day. Evaporation
from water surfaces on land would not be enough to keep rivers and lakes full and
provide the human population with drinking water. Fortunately, large amounts of
water evaporated from the seas and oceans are carried by air masses onto land where
condensation and precipitation take place.
 Condensation is the process by which water vapour changes into water droplets. It
happens when water vapour is cooled to a level known as the dew point.
Condensation forms cloud and can also occur at the surface as fog.
 Precipitation occurs when water in any form falls from the atmosphere to the surface.
This is mainly as rain, snow, sleet, and hail. Thus, water is constantly recycled
between the sea, air and land.

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51. Oral Johnson
The Drainage Basin System
When precipitation reaches the surface it can follow a number of different pathways.
A drainage basin is an area of land drained by a river and its tributaries. A drainage basin may
be described as an open system and it forms part of the hydrological or water cycle. If a drainage
basin is viewed as a system then its characteristics are:
 Inputs: how water is introduced into the drainage basin system. This is known as
precipitation.
 Stores: How water is stored or held for a period of time within the drainage basin system-
interception ( by vegetation), soil moisture, surface storage (lakes) and groundwater
 Transfers/flows : a process or flow of water from one place to another in the drainage
basin system- surface run-off/ overland flow, infiltration, percolation, through-flow,
throughfall and groundwater flow
 Outputs: How the water is released either back to the sea or back into the atmosphere-
evapotranspiration and river carrying water to the sea.

52. Oral Johnson
Elements of the drainage basin system
Precipitation forms the major input into the system. Precipitation occurs when water in any form
falls from the atmosphere to the surface. This is mainly as rain snow, sleet and hail. When
precipitation reaches the surface it can follow a number a different pathways. A small amount
falls directly into rivers as direct channel precipitation. The rest falls onto vegetation or the
ground. If heavy rain has fallen previously and all the air pockets in the soil (pore spaces) are full
of water, the soil is said to be saturated. Because the soil unable to take in any more water, the
rain flows on the surface under the influence of gravity. This is called surface runoff or
overland flow. Overland flow is common in urban areas where the surface is made up of
impermeable materials such as tarmac and concrete.
Rainwater can be intercepted by vegetation. Interception is the precipitation that is collected and
stored by vegetation. Interception is greatest in summer when trees and plants have most leaves.
Some rainwater is stored on leaves and then evaporated directly into the atmosphere. The
remaining intercepted water either drips to the ground from leaves and branches ( throughfall)
or trickles down tree trunks or plant stems (stemflow) to reach the ground.
The water that reaches the ground may then enter the soil as infiltration. Infiltration is the
passage of water into the soil. The maximum rate at which water can pass through the soil is
called its infiltration capacity and is expressed in mm/hr. Some of the water will flow laterally
through the soil (roughly parallel to the surface) as through flow.
If the soil is not saturated, rainwater will soak into it. If the rock below the soil is permeable
(allows water into it), the water continues to soak down deeper into the rock. This continuous
downward vertical movement of water into the rock is called percolation. The water eventually
comes to an impermeable rock (which does not allow water into it). The underground water level
builds up towards the surface from here to create a groundwater storage. Here all the pore spaces
are filled with water and is sometimes called a zone of saturation. The underground water does
not remain stationary but flows downslope under gravity (laterally). The upper boundary of
underground water or the upper level of the saturated material is known as the water table.
Water contained in rocks is known as ground water. The groundwater may then be slowly

53. Oral Johnson
transferred laterally as groundwater flow or base flow. The flow of groundwater is much slower
than runoff with speeds usually measured in centimeters per day, meters per year or centimeters
per year. Rock that holds ground water is known as an aquifer.
Water is lost from the system by evaporation and transpiration. Vegetation takes moisture
through its root system. It loses some of this into the air by transpiration. Surface water is also
lost by evaporation. The combination of the two is known as evapotranspiration. Once in the
river, water flows toward the sea and is lost from the drainage basin system.
Drainage basins
A drainage basin (or catchment area) is the area drained by a river and its tributaries. The
boundary of a drainage basin. The boundary of a drainage basin is called a watershed. This is a
ridge of high land that separates one drainage basin from another. The point where a river begins
is its source. A river reaches the sea at its mouth. A tributary joins the main river at a confluence.
A main river and all its tributaries form a river system. For example, the Mississippi and its
tributaries drain over one-third of the USA. Watershed in the Caribbean islands are typically
‘pear-shaped’: they are broad along the upstream divide and relatively narrow near the sea. In the
volcanic Windward Islands, watershed are steep and deeply dissected.
When small stream begin to flow they act under gravity, following the fastest route downslope.
Along the way water is added to them from tributaries, groundwater flow, throughflow and
overland flow.

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The source of a river
The starting point of a river may be:
 An upland lake

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 A melting glacier
 A spring in a boggy upland area where the soil is saturated that recognizable surface flow
begins
 A spring at the boundary between permeable and impermeable rocks
Drainage Density
Some big rivers have a large number of tributaries so that no place in the drainage basin is very
far from a river or stream. Such an area is said to have a high drainage density. Where a main
river has few tributaries the drainage density is low. High drainage densities occur where:
 The bedrock is impermeable
 The soils are easily saturated
 Precipitation is high
 Slopes are steep
 Interception by vegetation is limited
Where drainage density is high, water reaches streams quickly. It moves rapidly through the
basin. Therefore the flood risk is high compared with basins with low drainage densities. In the
Windward Islands, for example, drainage density is relatively high due to the steep slopes and
the volcanic nature of the islands. However, in the coralline/limestone Leeward Islands, slopes
within watersheds tend to be gentle with relatively low drainage densities. In these watersheds on
limestone there is significant percolation into rocks which builds up groundwater reserves.

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Drainage patterns
River systems often form a distinct pattern which is due to the structure of the rocks in the
drainage basin. The point at which one river or stream flows into another is known as the
confluence. Three distinctive patterns can be recognized, dendritic, trellis and radial.
Dendritic
This pattern looks like tree branches. This pattern develops in gently sloping basins with fairly
uniform rock type. The tributaries flow into the river at random forming a pattern like the veins
of a leaf. Examples of dendritic drainage are in the Caroni River in Trinidad and the Bruce Vale
river basin in Barbados. This type of drainage pattern is the most common in the Caribbean
region.
Trellis
This drainage pattern has an appearance of a rectangular grid. Rivers and their tributaries flows
almost perpendicular to each other with confluence of almost 90o. Trellis drainage takes place
where there is an alternate band of hard and soft rock at right angles to the main direction of the
slope. The main river has the power to cut though the hard rock while the tributaries cut though

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the softer rock at more or less right angles. This pattern can be seen in some areas of western
Barbados and is also present in the Northern range of Trinidad.
The principal river which flows down the slope is called a consequent river (C) next the
tributaries which cut out the vales and which do not flow down the main slope are called
subsequent rivers (S).
Radial
Radial drainage patters happens on a dome or volcanic cone. This pattern resembles the spokes
of a wheel. The river radiates outwards in all directions from a high central point or dome. The
volcanic islands in the eastern Caribbean have radial drainage pattern. The southern half of St.
Lucia and Nevis are good examples of where radial drainage takes place.

58. Oral Johnson
Rivers: energy and processes
Energy is needed for transfers to occur. Around 95% of rivers energy is used to overcome
friction. The remaining 5 percent or so is used to erode the river channel and transport material
downstream. The amount of energy in a river is determined by:
 The amount of water in the river
 The speed at which it is flowing
Near the source, river channels are shallow and narrow. Also the bed is often strewn with
boulders and very uneven. High levels of friction upstream can cause considerable turbulence.
The water flows more slowly here than further downstream where the channel is wider, deeper
and less uneven. Although the river is unique, most show similar changes from source to mouth.
Three sections can be recognized along rivers: the upper course, middle course and the lower
course. Figure 3.3 show these sections which combine to form the long profile of the river. In
each section the main process taking place and the shape of the valley are different

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From source to mouth the rivers
 Gradient decreases
 Depth increases
 Width increases
 Volume increases
 Velocity increases
 Discharge increases
The volume is the amount of water in the river. The velocity is the speed of the water. The
discharge is the volume times the velocity. Discharge is defines as the amount of water passing a
specific point at a given time. It is measured in cubic meters per second m3/ sec. The discharge
rate can also show big variations between dry and wet seasons. The Amazon has the world’s
highest discharge at around 219000m3/sec
Erosion
There are four processes of erosion
Hydraulic action

60. Oral Johnson
The pressure of water breaks away rock particles from the river bed and banks. The force of the
water hits river banks, and then pushes water into cracks. Air becomes compressed, pressure
increases and the riverbank may, in time collapse. Where velocity is high e.g. the outer bend of
meaner, hydraulic action can remove material from the banks which may lead to undercutting
and river bank collapse
Corrasion (or abrasion)
This is the wearing away of the bed and banks by the rivers load. This is the main type of erosion
in most rivers. Where depressions exist in the channel floor the river can cause pebbles to spin
around and turn hollows into potholes.
Attrition:
When pieces of rocks are broken away from the bed and banks the edges are usually sharp.
However, in swirling water rocks and stones collide with each other and with the bed and banks.
Over time the sharp edges become smooth and the pieces of rock become smaller in size.
Corrosion or Solution
Some rocks, such as limestone, dissolve slowly in river water which contains dissolved carbon
dioxide from the air. This process is common where carbonate rocks such as limestone and chalk
are evident in a channel

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Most erosion occurs when discharge is high and rivers are said to be in flood. Erosion acts on the
landscape in three ways:
 Near its source a river cuts down into its bed, deepening the valley. This is vertical
erosion
 In the middle and lower courses sideward or lateral erosion is most important. This
widens the valley
 Headward erosion takes place at the source. it causes the valley to grow very slowly
upstream.
Transportation
The load is the total amount of material being carried by the river. There are four processes by
which a river can transport its load: traction, saltation, suspension and solution.
Traction
Traction occurs when the largest cobbles and boulders roll or slide along the bed of the river. The
largest of these may only be moved during times of extreme flood.
Saltation
Saltation occurs when pebbles, sand and gravel are temporarily lifted up by the current and
bounced along the bed in a hopping motion. They are too heavy to carry in suspension
Suspension
Suspension is when material made up of very fine particles such as clay and silt is lifted as the
result of turbulence and transported by the river. Faster-flowing, turbulent rivers carry more
suspended material. The material held in suspension usually forms the greatest part of the total
load; it increases in amount towards the river’s mouth, giving the water its brown or black color.
Solution

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Solution is when dissolved material is carried by a river. Water flowing within a river channel
contains acids (e.g. carbonic acid from precipitation). If the bedrock is soluble, like limestone, it
is constantly dissolved in the running water and removed in solution.
Deposition
When the velocity of a river begins to fall, it has less energy and so no longer has the
competence or capacity to carry all its load.
Deposition occurs when:
 Discharge is reduced following a period of low precipitation
 Velocity is lessened on entering the sea or a lake (resulting in a delta)
 The gradient decreases significantly
 The current slows on the inside of a meander
 The river overflow its banks so that the velocity outside the channel is reduced.
When a river loses energy the first part of the load to be deposited is the large, heavy material
known as the bedload. Lighter material is carried further. The gravel, sand and silt deposited is
called alluvium. This is spread over the flood plain. The solution load- the lightest suspended
particles which include clay- is carried out to sea. Some rivers get their name from the colour of
the silt that they carry, for example the Yellow River in China.

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THE UPPER COURSE
The many features/landforms in the upper course of a river are:
 V-Shaped Valleys
 Interlocking spurs
 Potholes
 Rapids
 Waterfalls and Gorges
Rapids
Sometimes very thin alternating bands of hard and soft rock cross the course of a river. The
softer rocks wear away/erodes faster than the harder rocks. This is known as differential erosion.
The softer rocks are then on a lower level compared to the harder rocks. This creates an uneven
river bed and the river falling in a series of steps along the bands of the hard rock to form a zone
of turbulent water known as rapids

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Potholes
Where the bed is very uneven, pebbles carried by fast, swirling water can become temporarily
trapped by obstacles in the bed. The swirling currents cause the pebbles to rotate in a circular
movement, eroding circular depressions in the bed (abrasion). These are potholes. They general
increase in size only very slowly.
Interlocking Spurs
The river wind its way (meanders) around obstacles of hard rock. Erosion is concentrated on the
outside banks of these small meanders. This eventually creates spurs which alternate on each
side of the river, so they interlock. A spur is a ridge of high land which project towards a river at
right angles, decreasing in height towards the river.

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Waterfalls
Waterfalls are the most spectacular feature of the upper course, but they can also be found in the
middle course. This occur when there is a sudden change in the course of the river. This may be
due differences in rock hardness along the valley or for several other reasons:
 A steep drop at the edge of a plateau has been formed by uplift of the land
 A lava flow crosses the path of the river which pours over its edge as a waterfall
Waterfalls can form when the rock is horizontal, vertical or dipping upstream. The lower softer
rock is eroded more quickly causing the hard rock to overhang. The undercutting is caused by
corrosion and hydraulic action, with water swirling around in the plunge pool and spray hitting
the soft rock as the water plunges over the waterfall. The overhang steadily becomes larger until
finally it collapses. The rocks that crash down into the plunge pool are swirled around by the

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currents. This increases erosion and makes the plunge pool deeper. The rocks in the plunge pool
are eroded mainly by attrition.

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This process, beginning with the collapse of a layer of hard rock, is repeated multiple times. As a
result the waterfall retreats upstream, leaving a steep-sided gorge.

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V-shaped valleys
In the upper course much of the rivers energy is needed to overcome friction. The rest is used to
transport the load. The river in this section contains large boulders which can erode the bed
rapidly when the river is in flood. This results in the river cutting downwards into its bed, a
process known as vertical erosion. It forms steep V-shaped valley. Soil and loose rock on the
valley sides are washed down the steep slopes into the river. This adds to the load

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THE MIDDLE AND LOWER COURSES
In the middle course of the river profile the gradient is much less than in the upper course. The
volume of the water increases, with more tributaries joining the main river. More water is added
by through flow and, if the rock is permeable, by groundwater flow. Lateral erosion takes over
from vertical erosion as the most important process. Channel is much wider.
The lower course is nearest to the sea. The gradient is gentler. This section is characterized by
an even greater volume of water and higher velocity. Deposition is now much more important
than erosion. Meanders are more pronounced. The valley has the shape of an Open V in cross
section.
River cliffs and Point bars
Meanders occur in the middle course and are the result of erosion and deposition processes
operating in the river. The current is fastest and most powerful on the outside of the meander.
Within the river the fastest current is on the outside of the bend and the slowest current on the
inside of the bend. The concave or outside bend is much deeper so less friction and a higher
velocity.
Erosion is relatively rapid and the outside bank (concave bank) is undercut. Eventually the bank
collapses and retreats, causing the meander to spread across the valley. If the meander has
already reached the side of the valley, erosion on the outside bend may create a very steep slope
or river cliff. The current on the inside (convex bank) of the meander is much slower. As the
river slows it drops some of its load and deposition occurs. This builds up to form a gently
sloping slip-off slope, or point bar. Thus the water is shallow on the inside of the meander and
deep on the outside.
Diagram showing processes operationg on the inside and outside banks of a meander

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Diagram showing erosional and depositional actions of a river as it flows around a
meander

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Diagram showing a cross section of a meander
Meander migration
Because of the power of lateral erosion in the middle course, meanders slowly change their shape
and position. As they push sideways they widen the valley. But they also move or migrate
downstream. This erodes the interlocking spurs, giving a much more open valley compared with
that in the upper course.
Diagram showing how meanders migrate downstream

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Flood plain
A flood plain is the area of almost flat land on both sides of a river. It is formed by the movement
of meanders explained above. Meanders are more pronounced in the lower course. The
floodplain is constantly build up by flooded alluvial deposits. After each flood new layers of
alluvium are formed. This gradually builds up the height of the flood plain. The flood plain is
much more pronounced in the lower course as the river develops a very wide and flat valley
floor.
Diagram below show the flood plain

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Levees
When discharge is high the river is able to transport a large amount of material in suspension. At
times of exceptionally high discharge the river will overflow its banks and flood the low-lying
land around it. The sudden increase in friction as the river water surges across the flood plain
reduces velocity and causes the material carried in suspension to be deposited on the flood plain.
The heaviest or coarsest material will be dropped nearest to the river. This can form natural
embankments alongside the river called Levees. Levees are sometimes strengthened by engineers
to control flooding.
The lightest material is carried towards the valley sides. Each time there is a flood a new layer of
alluvium is formed. This gradually builds up the height of the flood plain.
Diagram showing the development of a Levee

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Meander necks and Ox-bow lakes
As a river flows from its middle course to its lower course, meanders become even more
pronounced and the valley becomes wider and flatter. Oxbow lakes are shallow, crescent shaped
lakes found on the flood plain and are the remains of a former course of a river.
An oxbow lake develops when a meander becomes so pronounced that only a narrow neck of
land separates the two ends of the meander. Erosion continues to cut into outside bends of the
meander and a meander neck is form. With continuous erosion the meander neck becomes
narrower and narrower. Eventually, when the river is in flood and discharge is high, it may cut
right across the meander neck following a more direct route and shortening its course. For a
while water will flow along both the old meander route and along the new straight course.
However, because the current slows down at the entry and exit points of the meander, deposition
will occur. After a time the meander will be cut off from the new straight course, leaving behind
an Ox-bow lake. When cut-off occurs the only sources of water for the ox-bow lake will be

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precipitation and flooding from the river. If evaporation is greater than these additions of water
the ox-bow lake will eventually dry up
Diagram the development of an oxbow lake
Braiding or braided rivers
Braiding is when a river divides for various distances into two or more channels. The channels
are separated by islands of sediment. Braiding occurs when:
 A river carries a very large load, particularly of sand and gravels, in relation to its
velocity.
 The discharge changes rapidly from season to season.
During a dry period or by increase load the river may not be capable of carrying its full load, and
so a great deal of deposition takes place on the bed of the river and the river channels become

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choked. This give rises to sandbanks and small islands in the bed. The river is forced to split up
into several channels (known as braided and its way through its own deposits. This is known as a
braided river.
Diagram showing a braided channel
Deltas
Deltas are formed by the deposition of sediments at the mouth of a river as it enters a sea or lake.
Deltas only form under certain conditions and most rivers do not end in a delta.
Large rivers in the lower course have the energy to transport a great deal of material in
suspension. As a river enters the sea its speed of flow is reduced, sometimes very suddenly,
causing deposition. The coarsest materials (like sand) is deposited first because of a greater
weight, while finer material (like clay) are carried out further into the sea. Thus layers of
different sediments are built up on the sea floor until they reach the surface. This happens first at

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the landward end of a delta, extending gradually out to sea. This huge platform of river sediment
is called delta.
A delta is therefore an accumulation of sediments at the mouth of the river which has been
formed by deposition of successive layers of sediments. When a river flows into a delta it has to
flow over its own deposit. This causes the river to braid. Each channel in a delta is called a
distributary.
The two main conditions required for deltas to form are:
 The river must have a large amount of sediment
 Coastal currents and waves must not be so strong as to remove sediment faster than the
river can deposit it- if this happens the sediments are spread over a much wider area of
sea floor beyond the mouth of the river.
There are three main types of delta:
 Fan-shaped or arcuate: This is triangular in shape with a slightly rounded outer margin.
The Nile and Yallahs River in Jamaica are examples
 Bird’s foot or digitate: distributaries flanked by sediment extend out to sea like the
claws of a bird’s foot. The Mississippi delta is a good example.
 Estuarine or cuspate: the delta forms an islands in the river’s mouth. The Amazon, and
Essequibo river in Guiana are examples
Major deltas are not common in the Caribbean. This is because it usually takes a large river to
build out into the sea.
Diagram showing the structure of delta

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LIMESTONE
Limestone is the name given to rock which is composed mainly of calcium carbonate. Calcium
carbonate is a chemical compound of calcium, carbon and oxygen. The chemical formula for
calcium carbonate is CaCO3. Limestone is a sedimentary rock which is formed underwater.
Some limestone consists mainly of coral or the shells of other small marine creatures. Limestone
may also be precipitated from seawater.
Limestone is a permeable rock. This means that water can enter limestone through pores, joints
or cracks in the rock. Another characteristic of limestone is that it can be slowly dissolved by
water. When groundwater or rainwater absorbs carbon dioxide, it becomes a weak acidic
solution which is especially effective at dissolving limestone. Because of these simple facts,
wherever limestone is in contact with rainwater or groundwater, some interesting limestone
features tend to develop.
Carbonation
Carbonation is the most important form of chemical weathering in limestone areas, whether they
are in tropical or temperate zones of the world. Rainwater containing carbon dioxide absorbed
from the atmosphere is able to dissolve calcareous (calcium–based) rocks. Carboniferous
limestone and chalk are the types of limestone affected most because they are made of almost
pure calcium carbonate.
Here are the stages of the process:
1) Rainwater dissolves carbon dioxide from the air as it passes through it
H2O + CO2 = H2 CO3
Rain water + Carbon dioxide = Mild carbonic acid
2) The mildly acidic rainwater reacts chemically with the calcium carbonate in the rock
H2 CO3 + CaCO3 = Ca (HCO3)2
Mildly acidic rainwater + calcium carbonate = Calcium bicarbonate
3) Calcium bicarbonate is soluble in water so it is easily washed away

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Common Limestone Features
Surfacefeatures
Clints and Grikes
A limestone pavement is a natural karst landform consisting of a flat, incised surface of
exposed limestone that resembles an artificial pavement. This pavement is filled with joints.
Carbonic acid will attack the joints and overtime a small depression called a grike will form.
Clints are upstanding features that are formed on the areas of the pavement that resisted erosion.
Sink holes or swallow holes: A sink hole (or swallow hole) is a natural depression or hole in the
Earth’s surface commonly found in limestone areas. They are formed when joints or fissures in
the rock are enlarged by carbonation or when the roof of an underground cavern collapses.
Sometimes a river or stream may “disappear” down a sink hole and continue flowing
underground.
Dolines

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Dolines are large depressions formed by the solution or collapse of limestone. Frequently they
are covered by other deposits. Depressions can range from small-scale hollows to large
depressions up to 30m in diameter
Cockpits (depression) and Cones (hills)
In many limestone areas, the chemical weathering processes of solution and carbonation have
produced distinctive landscapes known as karst landscapes. Karst landscapes are dominated by
features such as sinkholes, disappearing streams and caves. One well known karst landscape in
the Caribbean is the Cockpit Country in Jamaica.
The Cockpit country is a large area with many small hills and depressions. This karst landscape
was formed in an area with white limestone. In this area, the rock has many joints. These joints
cross each other as some run from east to west and others run generally from north to south.
Water collects in these joints. Therefore the rock near the joints is dissolved relatively quickly
forming depressions called COCKPITS. Small hills called CONES form in areas which are
further away from the joints as the rock in these areas is not dissolved as quickly. The photo
below shows a small part of the Cockpit Country.
Depressions
are cockpits
Hard rocks
stand up as
cones or hills

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Resurgent streams
Resurgent stream arise when the limestone is underlain by an impermeable rock, such as clay.
This force the water out into the open, forming a spring or resurgent stream. There are many
caves and sinkholes within the Cockpit Country. No rivers or streams can be found on the
surface in the area because they have all disappeared into swallow holes and flow underground
through caves.
Underground features
Caves: A cave is a naturally occurring underground hollow or passage, especially one with an
opening to the surface of the Earth. Caves often form in limestone areas when underground water
dissolves the rock, forming tunnels passages and even large caverns. There are several caves in
Barbados, the most famous of which is Harrison’s cave. Part of Harrison’s Cave can be seen in
the photo below.
Many interesting limestone features can be found within limestone caves. Some common ones
are stalactites, stalagmites and pillars.

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Stalactites: Water dripping from the ceiling of a cave contains dissolved calcium carbonate.
Some of this calcium carbonate may be deposited on the ceiling of the cave. Over time the
deposition of calcium carbonate will form an elongated feature which hangs down from the
ceiling. This feature is known as a stalactite. Several stalactites can be seen in the photo above.
Stalagmites: As water drips from the ceiling onto the floor of the cave, calcium carbonate may
be deposited on the floor of the cave. Over time this may form an elongated feature which rises
vertically from the cave floor. This feature is known as a stalagmite. Several stalagmites can be
seen in the photo above.
Note: A simple way to avoid confusion is to remember that stalactite has a “c” for “ceiling” and
stalagmite has a “g” for “ground”.
Pillars: A stalagmite may form directly below a stalactite as water drips from the ceiling of the
cave onto the floor. The stalactite may continue to grow downwards and the stalagmite may
continue to grow upwards until the two limestone features eventually meet. When this happens
they form a new feature known as a pillar or column which extends all the way from the ceiling
of the cave to the floor. A limestone pillar can be seen in the photograph below.

85. Oral Johnson
COASTS
Waves are the most commonly formed by friction as the wind blows over the surface of the
sea.
What cause waves to break?
In deep water the surface waves form part of a circular movement of water. This explains why
there is actually horizontal movement of water in the oceans. However, look what happens as the
waves get nearer to the coast:
 As the sea near the shore is shallow the circular motion of the waves is interrupted by
friction with the seabed
 The water motion becomes more elliptical ( shaped like a rugby ball)
 The wave grows in height and begins to topple forward
 Eventually the waves break on the shore. Water moves up the beach as the swash and
then drains back down the beach as backwash.
When waves near the coast, the bottom of the wave is slowed by friction with the sea bed.
Because the top of the wave is experiencing less friction, it moves faster and eventually
topples over the bottom of the wave and breaks.

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The power of the waves when they reach the coast depends on three factors:
 The distance of open water over which the wind has blown. This is called the fetch.
The longer the fetch the more the powerful the waves
 Strength of the wind- The stronger the wind the more powerful the waves.
 Duration of the wind – If strong winds have blown over a long period of time, this will
result in powerful waves.
Wave Terminology
Crest: The top of the wave. Trough: The low area in between two waves. Wavelength: The
distance between two crests or two troughs. Wave height: The distance between the crest and
the trough.
Wave Frequency: The number of waves per minute. Velocity: The speed that a wave is
traveling. It is influenced by the wind, fetch and depth of water. Swash: The movement of water
up the beach. Backwash: The movement of water back down the beach after the swash is
completed
Constructive and Destructive waves
It is possible to identify two types of waves:
Constructive Waves:
Constructive waves are low but powerful waves that surge up the beach when they break. Their
swash is much more powerful than their backwash, much of which percolates through the
beach as the water flows back to the sea. Constructive waves are created by storms many miles
away from the coast and they travel fast across the ocean.
They are called ‘constructive’ waves because they transport beach material to the top of
the beach, thereby ‘constructing’ it. Because the swash is stronger than the backwash they tend
to deposit material and build beaches up

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Destructive waves
Destructive waves are essentially the opposite of constructive waves. They are taller and tend to
crash down onto a beach rather than surging up the beach. There is little swash but the backwash
is powerful. This leads to erosion of the lower beach, hence the term destructive. Destructive
waves are usually formed during local storms that are centered close to the coast.
Because the backwash is stronger than the swash, destructive waves erode and transport
material away from beaches.

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COASTAL EROSION AND EROSIONAL FEATURES
Abrasion/Corrasion:
When waves approach the coastline they carry material such as sand, shingle, pebbles and
boulders. Abrasion occurs when these materials are hurled against cliffs as waves hit them,
wearing the cliff away. It is the most effective method of erosion
Hydraulic action- This occurs when water is thrown against the land by breaking waves, thus
compressing the air which is contained in any cracks in the rocks. When the wave retreats the air
expands, thus exerting pressure on the rocks. When repeated over a long period of time, the
expansion of air in the cracks may cause the rocks to shatter.
Attrition
As in the case of material carried by rivers, the material carried by waves also becomes broken
into smaller fragments. This is the result of the pieces of material hitting against each other and
against the land. Beach material is knocked together in water reducing their size and increasing
their roundness & smoothness. THIS PROCESS IS NOT RESPONSIBLE FOR THE EROSION
OF CLIFFS.
Corrosion/solution:
Seawater contains carbonic acid, which is capable of dissolving limestone. The dissolving of
soluble rock, such as limestone.
Coastal Erosion is most effective when the waves are powerful and contain a lot of energy.
These waves need to break at or close to the foot of a cliff if they are to carry out erosion.
Features of Coastal Erosion
Headlands and Bays
Bays and headlands are formed in a very similar way to rapids (rivers topic). They are formed
when you get alternate layers of hard and soft rock. Alternating layers of hard and soft rock
allow the sea to erode the soft rock faster, forming a bay but leaving hard rock sticking out,
known as a headland. The altering rate of erosion of hard and soft rock is known as differential
erosion.

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Bay: An indented area of land normally found between two headlands. Bays are usually more
sheltered so there is less erosive power, meaning you often find beaches in bays.
Headland: A piece of land that sticks out into the sea. Waves refract around headlands so they
experience a lot of erosion forming features like arches and stacks
Wave cut notch and Wave cut platform
A wave cut notch is simply a small indent at the base of a cliff formed when a cliff is undercut
by the sea. When a wave breaks on a cliff, all of the wave’s energy is concentrated on one
specific point and this section of the cliff experiences more rapid erosion via corrosion and
hydraulic action. This eventually leads to the formation of a wave cut notch, when the cliff has
been undercut
Wave cut platforms are made in a similar ways to waterfalls and gorges (rivers topic). At high
tide the power of the sea attacks and erodes the bottom of the cliff. Over time this erosion creates
a wave cut notch (basically an eroded hole at the base of the cliff). As the wave cut notch gets
bigger, the weight of rock above the notch gets greater. Eventually the cliff cannot support its
own weight and it collapses. The process then starts again, with the erosion of the sea making a

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new wave cut notch. As the process continues the cliff starts to move backwards (retreat).
Because the cliff is moving backwards a wave cut platform (an expanse of bare rock) is created.
Caves, Arches, Stacks and Stumps
Waves are particularly good at exploiting any weakness in a rock, such as a joint.
Caves
Caves occur when waves force their way into cracks in the cliff face. An increase in erosional
activity can widen the crack over a period of time until it is large enough to form a cave. The
dominant processes of erosion are abrasion/corrasion.
Arch
An arch is formed when two caves develop on each side of a headland. With continuous erosion
they will grow in size and eventually meet giving rise to a feature known as an arch.
Stack
The roof of the arch has no support however and is highly susceptible to weathering via
exfoliation, salt crystallisation and biological weathering. As the weathering continues, the roof
of the arch will collapse leaving a stack, a tall, lone piece of land sticking out in the sea.

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Stump
This stack is exposed to the full force of the water and is weathered and eroded heavily. The base
of the stack receives a lot of erosion from hydraulic action and corrosion and, eventually, the
stack will collapse into the sea leaving behind a small piece of land called a stump.
Caves, arches, stacks and stumps are usually found on headlands, where wave refraction is
causing erosion on three sides. The waves always look for weaknesses in the headland (cracks
and joints). If they find a crack or a joint they will start attacking it. Hydraulic pressure will be
the main type of erosion. Overtime the crack may turn into a cave. Slowly the cave will get
bigger and cut all the way through the headland, making an arch. As the arch gets bigger the
weight of the arch roof gets too great and it collapses, leaving a stack. The stack is then eroded
by the sea leaving a stump.

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Blowhole: Cave sometimes develop in the face of cliffs. They develop when there is a weakness
in the rocks, which is enlarged by wave action. Waves pounding against cliffs can exert great
pressure, which causes the air in the cracks to be suddenly compressed. The alternate

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compression and expansion of the air in the cracks enlarges them, and in time they may develop
into caves.
If there are vertical joints leading from the roof of the cave to the top of the cliff, these also may
become enlarged. In time a passageway may be opened up, through which air and water can
escape to the surface at the top of the cliff. Such feature is known as a blowhole.
LONGSHORE DRIFT AND COASTAL DEPOSITON FEATURES
There are many different types of sediment at the coast including beautiful white coral sand, the
more common yellow sand, pebbles (shingle) and mud. Once rock fragments have been broken
off a cliff or brought to the coast by rivers, they enter the coastal (littoral) transport system.
Waves are very effective transporters of sediment. After a storm, beaches can look very
different.
Coastal transportation
Sediment is moved by the waves in a number of ways.
Traction: This is where heavier particles are slowly rolled along the sea bed.
Saltation: Some particles move in a bouncing manner as they are disturbed by other particles
knocking into them. They are too heavy to be carried by the water but light enough to ‘hop’
along the sea bed.

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Suspension: Lighter particles can be picked up and carried within the water. Sand is most
commonly transported in this way.
Solution: Dissolved chemicals will be transported in solution. Limestone (calcium carbonate) is
often transported in this way before precipitating out of solution to form new limestone deposits
on the sea bed. This is a very common process in the warm Caribbean seas.
Coastal deposition
One important factor affecting the movement of sediment and its deposition at the coast is the
angle at which the waves approach a shoreline. If the waves approach parallel to the coast,
sediment will simply be moved up and down the beach. There will be very little movement along
the coast. Under these conditions beaches will form in bays
If the waves approach a shoreline at an angle, sediment is transported along the coast in zig-zag
fashion. This process is called longshore drift and it results in a pile up of sediment at one day of
a bay.
Coastal deposition takes place in areas where the flow of water slows down. Sediment can no
longer be carried or rolled along and it has to be deposited. Coastal deposition most commonly
occurs in bays where the energy of the waves is reduced upon entering the bay. This explains the
presence of beaches in bays and accounts for the lack of beaches at headlands where wave
energy is much greater.
Longshore Drift
This is the process of waves moving (transporting) material (load) along a coastline. When
Waves approach the shore at an angle (usually in line with prevailing wind direction) the swash
moves material up the beach in this direction. Backwash pulls material straight down the beach.
The result is that material is transported in a zig-zag fashion.
Longshore drift only happens when the waves hit the beach at an angle. It is the process of the
swash transporting material up the beach at an angle and the backwash returning directly under
the force of gravity that causes material to be transported along the beach.

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Features of Coastal Deposition
Beaches
The best known feature resulting from deposition by waves is the beach. This may be made up of
mud, sand, shingle (small rounded stones) or boulders. Beaches are the result of longshore drift
produced by constructive waves. Beaches usually have a gently sloping surface. They are
generally formed between high and low tide marks. Sometimes, however, stormy conditions at
high tide may throw material up beyond the high tide mark, resulting in what is known as a
storm beach.
Most beaches in the Caribbean are made up of sand. Sandy beaches are most often found in
sheltered bays where they are called bayhead beaches. When waves enter these bays they are
forced to bend to mirror the shape of the coast. This is called wave refraction. It is caused by the
shallowing of the water as the waves enter the bay. Refraction spreads out and reduces wave
energy in a bay, which is why deposition occurs here.

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Spit
A spit is a long, narrow finger of sand or shingle jutting out into the sea from the land. Spits are
very common features across the world. It is formed when sediment transported along the coast
by longshore drift is deposited at a bend in the coastline (usually at a headland). Even though
there is a change in shape of the headland longshore drift will continue and sediments will be
continuously deposited. With continuous longshore drift and deposition the spit will gradually
extend out into the sea further and further away from the mainland. The spit will become larger
over time.
Over time a spit become colonized by grass and bushes, and eventually trees will grow. On the
sheltered landward side of a spit, where the water is very calm, mudflats and salt marshes will
form. These are important habitats for plants and birds. The end of the spit is usually hooked
because of occasional winds and storms that blow in the opposite direction of the prevailing
wind called secondary winds. The spit will never grow across to the next side of the headland
because the fast flowing river will disturb any deposition.

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Tombolo
Tombolos are created through the process of longshore drift. A tombolo is formed where a spit
continues to grow until it reaches an island, forming a link with the mainland, just like bridges.
This feature is known as a tombolo. The island of Scotts Head on the south coast of Dominica
has become attached to the mainland by a tombolo as a result of deposition of sediment by
longshore drift from east to west. The Palisadoes tombolo just south of Kingston, Jamaica is a
highly complex 13km tombolo that connects several offshore cays. It is the site of Kingston’s
Norman Manley International Airport.

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Bar
A bar is a long narrow deposit of sand or shingle that usually forms parallel to the coast. There
are two main types of bar:
Baymouth Bar
Occasionally a sand or shingle spit extends right across a bay to form a baymouth bar. There is
often water trapped behind the in the form of a fresh water lake or lagoon.

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Offshore bar
An offshore barrier bar is a narrow sand or single deposit that runs parallel to the coast just out to
the sea. Along some stretches of coastline tidal currents and waves combine to cause a build-up
of sediment on the sea bed just offshore. This feature is called a sandbank or offshore bar and it
is very often extends for several kilometers parallel to the coast. The calm. Shallow water
trapped between the offshore bar and the coast is called a seawater lagoon.
Offshore bars may lie just below the surface of the water, combed flat by breaking waves, or
they may emerge over time to form barrier islands. The barrier off the coast of Miami in Florida
form the densely urbanized part of the city called Miami Beach.

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101. Oral Johnson
CORAL REEFS AND MANGROVES ECOSYSTEMS
CORAL REEFS
What is a Coral Reef
A coral reef is a hard, rocky ridge built up from the sea by many tiny coral animals. It is one of
the richest ecosystems on Earth and is sometimes called the ‘rainforest of the sea’. Some living
reefs are several million years old.
Why are coral reefs valuable ecosystems?
Coral reefs are extremely important ecosystems providing a range of benefits. An estimated 500
million people depend on coral reefs for food, coastal protection, building materials and income
from tourism. About 30 million people are totally dependent on coral reefs for their livelihoods
or because they live on atolls. The main benefits of coral reefs include the following:
 Coastal protection: coral reefs act as buffer zones providing vital shoreline protection
from storms and tsunamis. The shallow water above a reef forces waves to break early
before reaching the mainland shore. This reduces coastal erosion and risk of flooding.

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Corals also provide sheltered conditions for the growth of mangroves, which themselves
are important breeding grounds for fish.
 Beach development: The erosion of coral reefs creates the white sand that typically forms
the beaches of tropical coastlines. Some of this sand is extracted for the construction
industry to make cement.
 Ecological Benefits: Coral reefs are extremely diverse ecosystems. They provide a home
to over 25% of all known marine fish. One hectare of reef off Southeast Asia was found
to support over 2000 species of fish! Coral reefs are important breeding grounds for fish
offering shelter and food.
 Economic benefits: The global value of the world’s coral reefs has been estimated at
almost US $30 billion each year! In Hawaii alone, the benefits associated with tourism,
fishing and biodiversity amount to US$ 360 million a year. Coral reefs are extremely
important commercial fishing grounds providing some 25% of the total fish catch of low-
income countries. It is estimated that coral reef fisheries in East Asia feed over 1 billion
people. Coral reefs are extremely popular tourist destinations, providing a huge source of
income and employment for thousands of people. Millions of people visit the Caribbean
each year to enjoy its tropical beaches and coral reefs. Coral reefs are increasingly valued
for medicinal purposes. Scientists believe that some of the chemicals released by corral
species for self-protection could have applicants for the treatment of some viruses and
cancers.
Formation of coral reefs
Corals are formed by millions of coral polyps, tiny animals resembling overturned jellyfish!
They use excess carbon dioxide in the water, converting it into limestone to form solid reefs.
Corals need particular conditions in order to develop, survive and thrive. They grow best in
sunny, shallow, warm and clear water conditions. This explains why they are only found in
certain parts of the world.
The main factors controlling the development of corals are water temperature, depth, salinity and
turbidity together with the presence of beneficial algae and fish.

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 Temperature: Tropical corals only live in seawater that has an average temperature of
180
c and over. The ideal temperature is between 230
c and 250
c. Therefore, coral reefs are
mostly found in tropical latitudes. The exception is where warm ocean currents transfer
these conditions into subtropical regions such as Bermuda.
 Depth: corals feed on tiny algae, and they algae need light in order to photosynthesize
and grow. If there is not enough light, there can be no algae. This means that coral
develops only in relatively shallow water conditions where sunlight can penetrate the
water. In clear tropical waters coral can live as deep as 48m. Very few species are found
below this depth.
 Salinity: corals thrive in salty water where the salinity is between 30 and 40 parts per
thousand. They do not develop so successfully in areas where freshwater runoff enters the
sea at river mouths.
 Turbidity (water movement): some turbidity is necessary to distribute coral larvae, to
provide food and oxygenated water to the sedentary polyps, prevent smothering of the
polyps by sediment and to remove waste products. However, strong waves and currents
can inhibit or prevent coral reef formation. Under such conditions, sediment becomes
agitated reducing light and smothering coral and preventing feeding and respiration.
 Presence of beneficial algae and fish: Coral enjoys a symbiotic relationship with both
algae (zooxanthelae) and fish. This means that they benefit from their association with
one another. The algae live within the coral structures and up to 90% of the organic
materials produced through the process of photosynthesis is passed directly to the host
coral tissue. Fish are abundant in coral reefs, using them as sheltered breeding grounds.
Coral consume small fish using their tentacles to stun and kill the fish.

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Types of Coral reef
Fringing reef – A fringing reef is a shallow-water feature found close to and running parallel to
the shore. These refs are associated with many of the islands in the Caribbean. A fringing reefs
reef forms from the gradual accumulation of coral in ideal environment. Between the reef and the
shore is a shallow lagoon that is rich in marine life.

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Barrier reef- A barrier reef is a much larger feature than a fringing reef. It lies in deeper water,
much further out to sea. The Great Barrier Reef in Australia is the world’s best example of a
barrier reed. It runs for 2600 km off the east coast of Queensland and is made up of 3000
separate reefs and 900 islands. It has been designated a world heritage site. In the Caribbean
there is a barrier reef some 25km off the coast of Belize.
A coral atoll- A coral atoll is an isolated ring-shaped reef rising out of deep water. It is the
centre of an atoll is a lagoon. Coral atolls are largely concentrated in the Indian Ocean, for
example the Maldives.

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Evolution of Coral Reefs according to Darwins theory of subsidence
Causes of Coral Reef Degradation
There are a number of potential threats to coral reefs
Pollution
Solid Waste Pollution-Sometimes solid wastes are carried to the sea by rivers, these solid waste
blocks the sunlight from reaching the reefs which are necessary for the corals growth and
development.
Sewage pollution- sewage pollution is one of the major causes of coral reef degradation. Sewage
is rich in nutrients that foster the growth of excess algae a process called eutrophication. The
algae take up most of oxygen that are essential to the corals growth. Other marine animals
include fishes are affected which need oxygen to survive. The algae also block the sunlight from
reaching the reefs.
Agricultural pollution- Some agricultural inputs (pesticides, herbicides, fertilizers) that are
widely used in the Caribbean end up reaching the sea by direct run-off. Run-off from farms
inland can enter the river system eventually reaching the sea. Organic fertilizers increase the

107. Oral Johnson
growth of nitrogen in seawater, causing an overgrowth of algae, which 'smothers' reefs by cutting
off their sunlight.
Tourism related activity
Tourism has contributed to major development in the Caribbean. However, tourism activities
have contributed to the degradation of many coral reefs in the Caribbean.
1. Clearing of land for construction of hotels, roads- the removal of trees have led to
erosion and subsequent sedimentation of sea water. Direct sediments from constructional
activities also results in sedimentation. Sedimentation blocks sunlight from reaching the
corals and also chokes the corals.
2. Collection of corals- Tourists collects corals for souvenir purposes. This practice is
causing a serious damage to coral reefs in the world.
3. Some boats anchor on reefs to allow scuba diving and viewing
4. Trampling by divers- During diving or snorkelling tourists trample the reef sometimes by
walking on it
Sedimentation
Sedimentation involves the discharge of sediment from the mouths of rivers into the sea.
Following heavy rainfalls river may discharge huge quantities of sediment into the sea causing
the water to become cloudy and reducing the penetration of sunlight. This can reduce
photosynthesis and cause corals to die.
Increased rates of sedimentation are often associated with land degradation, such as deforestation
or soil erosion. Whenever the bare soil is exposed it is vulnerable to being washed away.
Removal of coastal Mangroves
Coastal mangroves are well known as nurseries for many of the fish and other animals that later
populate the coral reefs. This direct interaction between coastal mangroves and coral reeds
means that the loss of mangroves inevitably affects the reefs. In addition, the mangroves filter
the run-off from the shore removing many pollutants and nutrients that would reach the reefs and
damage them. Once the mangroves are removed, the dangers from pollution and sedimentation
are greatly increased.

108. Oral Johnson
Destructive fishing practices
These include cyanide fishing, blast or dynamite fishing, bottom trawling, and muro-ami
(banging on the reef with sticks). Bottom-trawling is one of the greatest threats to cold-water
coral reefs. Dynamites that are used are so powerful that it can destroy the reefs. Cyanides that
remain in water can also kill coral polyps.
Sea Urchins
Sea urchins feed on algae and prevent the algae growing out of control and swamping the coral.
In Jamaica, disease wiped out of large numbers of sea urchins following a hurricane in 1983.
This has led to a lot of damage. Whilst the presence of sea urchins benefits coral reef
ecosystems, too many sea urchins can cause excessive burrowing. This demonstrates just how
fragile reefs are- they are ecosystems that can easily be thrown off-balance and suffer as a result.
Global Warming
Corals are very sensitive to temperature change. A rise of just 1-20
C can have a significant
impact on the health of the coral and cause them to turn white. This is called bleaching. In
August 2005, severe bleaching affected 50-95 per cent of coral colonies in the Lesser Antilles
and killed more than half.
Bleaching occurs when unicellular organisms called zooxanthellae, which normally live within
the corals, become stressed by rising temperatures and are expelled. It is the zooxanthellae that
gives the coral reef its colour. When they lose their colour, the corals become more susceptible to
death from starvation or disease.

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Hurricanes
Hurricanes are common in the Caribbean during the summer months. Storm waves damage the
coral reefs and the heavy rains often wash large amounts of sediment into the seas, clouding the
normally clear waters. In 1980, Hurricane Allen reduced much of Jamaica’s reefs to rubble.
Plagues of starfish (Crown of Thorns Starfish)
Some starfish species can devastate coral reefs, killing up to 90% of reef-building corals. Plagues
of starfish may result from nutrients being washed into the sea from the land. These nutrients
may be linked to agricultural fertilizers.
Coral
Bleachi
ngA healthy
reef

110. Oral Johnson
Overfishing
Overfishing can lead to the loss of very important fish species. Parrot fish and sea urchins for
example are species that are in decline that protects coral reefs. Parrotfish are colourful and
voracious herbivores that spend up to 90% of their day eating algae off of coral reefs with their
beak-like teeth.
Crowns
of thorn
starfish

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Mangroves
What are mangrove wetlands?
Mangrove wetlands or swamps are coastal ecosystems found in tropical and subtropical regions.
Mangroves are found extensively in the Caribbean as well as in many other regions around the
world. One of the largest mangrove swamps in the world is on Florida's southwest coast.
Mangrove swamps are characterised by halophytic (salt loving) trees, shrubs, and other plants
growing in brackish to saline tidal waters. These wetlands are often found in estuaries, where
fresh water meets salt water. They are famous for their dense maze of woody vegetation.
Caribbean mangrove wetland ecosystems
In the Caribbean there are three types of mangroves:
 Red mangroves: These are found closes to the sea and have their roots submerged at
high tide. They cope with high levels of salt by obtaining water from the ocean through a
process known as ‘reverse osmosis’. Inn this process, magnesium ions releases salt from
their roots enabling the plant to survive. The long arching aerial woody roots help anchor
the plant in the soft muddy sediment. It is through the roots that oxygen is obtained. The
roots also trap sediment helping to stabilize the coastal environment.

112. Oral Johnson

 Black mangroves: These are found further inland where conditions are saltier. They
cope by excreting the excess salt onto their leaves. Spongy structures called
pneumatophores protrude from the roots to stick out through the sediment rather like
periscopes. They can transfer oxygen direct to the roots.
 White mangroves: These are found further inland. Like the black mangroves they do not
have the extensive aerial root systems of the red mangroves. They also excrete salt onto
their leaves.

113. Oral Johnson
Mangroves swamps support a wide diversity of animals. They are constantly replenished with
nutrients that are transported by fresh water runoff from the land and flushed by the ebb and flow
of the tides. These ecosystems sustain billions of worms, protozoa, barnacles and oysters which
in turn feed fish and shrimp. These then support wading birds, pelicans, and the endangered
crocodile!
Why are mangrove wetlands important?
Mangrove wetlands are one the most important ecosystems in the world.
 Coastal protection: The dense tangle mangrove roots help to trap sediment. This created
an effective coastal defence against hurricanes, storm surges and tsunami. As sea level
rise due to global warming, mangroves will continue to grow and thrive, providing
lasting protection to coastal areas. If the mangroves are removed, the muddy sediment
quickly washes away leaving the coastline unprotected. In the tsunami of 2004, many
areas of Indonesia that were stull protected by their mangroves experienced relatively
little damage to human structures.
 Ecological (biodiversity) importance: Mangrove swamp provides valuable habitats for
many species of animal and fish which benefit from the calm, sheltered waters.
Mangroves are also very important to nearby coral reefs. They filter out silt and nutrients
that would otherwise go out to the reef, smothering the coral polyps and encouraging
algal growth. Mangrove swamps also serve as a breeding ground a nursery for young fish

114. Oral Johnson
 Socio-economic benefits: Mangrove swamps are popular tourist attractions despite the
biting insects! They are home to a wide variety of wading birds and crocodiles and
alligators. Mangroves provide many products and raw materials and they have significant
value for local communities.
Mangroves are mostly being destroyed to facilitate the construction of houses, hotels, roads and
industries.

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116. Oral Johnson
WEATHER AND CLIMATE
The layer of gases which surrounds the earth is called the atmosphere. The terms weather and
climate both have to do with the atmosphere, but they do not mean exactly the same, and they
cannot be used in place of each other. The term climate refers to the average as well as the
highest and lowest rates of temperature, rainfall, wind, cloud cover and air pressure over a period
at least 30 years. NASA defines climate as the description of the long-term pattern of weather in
a particular area. By contrast, the term weather refers to the atmosphere at a particular instant. In
general we talk about a few days or up to a week. The term micro climate refers to the distinct
climate associated with small areas such as a city, a woodland, a coastal area or even a school.
The main difference between weather and climate is time.
Factors affecting weather and climate
The factors that influences weather and climate are: latitude, altitude, distance from the sea and
relief/ topography.
Latitude
Temperatures decreases as you move away from the equator.

117. Oral Johnson
The further you move away from the equator the sun's rays are dispersed over a larger area of lan
d. In addition areas far away from the equator for e.g. the poles are cooler because the sun's rays
have a further distance to travel before reaching the earth's surface and some of the heat energy
would have lost during the journey.
At the equator the sun is often overhead. Therefore the rays of the sun fall directly or vertically at
the equator. It hits on a very small area so the heat gets concentrated in this area which gets very
hot. This causes the temperatures at the equator to be higher. In addition at the equator the sun’s r
ays have a shorter distance to travel through before reaching the earth's surface. As a result less h
eat is lost during the journey.
Relief/topography/ Mountain
Relief can influence the amount of precipitation an area receives. The winds which blow over the
Caribbean (over the Atlantic) are known as the north-east trade winds (NETW)
1) Rain-bearing wind – AS they (NETW) pass over the sea, they are able to take/pick up
moisture from the sea by the process of evaporation.
2) Air forced to rise – On meeting a mountain range (Blue Mountain) the rain bearing wind
is forced to rise over it. Upon rising the air cools and becomes less capable of holding
water vapor.
3) Condensation takes place- Because the air can no longer hold all the water vapor in it.
Some water vapor changes back into tiny drops of water. Millions of tiny droplets of
water accumulate together to form clouds over the top of the mountain range.
4) Precipitation- Heavy rainfall occurs on the top of the mountain range and on the
windward facing slope.
5) Air now descends – The air can now sink down the leeward side of the mountain and so
becomes warmer. The leeward side of the mountain range gets less rainfall than the
windward side because a) the air is now much drier, having deposited much of its
moisture on its journey over the mountain range b) the air is descending and getting
warmer, and so it can now hold much more water vapor than it would when rising. much
of its

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Parishes such as Portland and St Thomas in Jamaica receives between 1,200 and 1,800 mm
(47-70 inches) per year. Kingston receives about 800m (31.5 inches) of rain per year. This is
because it is sheltered from the trade winds.

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Altitude (Height Above sea level)
The atmosphere is not warmed directly by the sun. When the sun's rays heat the earth the heat fro
m the earth warms the air above it.
Water vapour and dust particles in the air prevent the heat from escaping into outer space, becaus
e they have the effect of trapping the heat forming a blanket/canopy over the earth's surface.
At higher altitude (the top of a mountain) the air contains very little vapor or dust. So little heat is
trapper at higher altitudes. In addition the air gets thinner because the molecules in the air which
receive and retain the heat became fewer and are widely space (less compact). As a result they ar
e not able to trap much heat to the earth's surface, the heat rapidly escape resulting in cooler temp
eratures.
In contrast at lower altitudes (bottom of a mountain) the air contains more vapor and dust particle
s. Therefore more heat is trapped. In addition, the air is also dense meaning the molecules in the
air which retain heat are more/greater and they are more compact. As a result the air is able to tra
p more heat to the earth's surface which results in warmer temperatures.

120. Oral Johnson
Temperature decreases by 6.50
c for every 1000m in height. This is called the Environmental laps
e rate. The environmental lapse rate is the decrease in temperature usually expected with an incre
ase in height through the troposphere.
Continentality/ Distance from the sea
This is of particular importance in those places which are far away from the equator. These
places have well developed summer and winter seasons. The sea has a moderating influence on
places close to it and they usually have moderate temperatures.
IN THE SUMMER
The sun's heat is absorbed and released more slowly by water than by land. The land absorbs
heat faster resulting in higher temperatures over land surfaces. The sea is cooler in the summer as
it takes up a longer time to heat up. Cool winds are brought onshore and this reduces the
temperature of coastal areas. As a result places near the coast tend to have cooler summers than
places further inland.
IN THE WINTER
In the winter the sea loses heat more slowly than the land. The sea is therefore warmer in the
winter. The land releases heat faster resulting in colder/lower temperatures over land surfaces.
Warm winds are brought onshore and this increases the temperature of coastal areas. Those
places further inland have really cold winters while those close to the coast have milder winters.

121. Oral Johnson
The places nearer to the sea have cooler summers and warmer/mild winters (maritime/oceanic
climate). They have a moderate climate due to the influence of the sea. Those further away and
further inland generally have extremes of climate that is really hot summers and very cold
winters (continental climate).

122. Oral Johnson
Caribbean Weather Systems
The weather systems that affect the Caribbean are: cold fronts, easterly waves, hurricanes,
intertropical convergence zone and Anticyclone
Cold Front
When air remains relatively stagnant over an area for some time, it takes on the temperature and
moisture characteristics of the area. Therefore, air which remains stagnant over a cold and dry
area will become cold and dry. Air which remains stagnant over the sea or ocean in the tropics
will become warm and moist. A body of air which has similar temperature and moisture
characteristics throughout is known as an air mass.
Over time, air masses may move out of the areas over which they develop. As they do so, they
encounter other air masses with different characteristics. When two air masses with different
characteristics meet, they do not readily mix. There is usually a sharp or well defined boundary
between the two air masses. This boundary is known as a front. There are different types of
fronts such as warm fronts and cold fronts. Warm fronts occur when a warm air mass moves
into a region of colder air. Cold fronts occur when a cold air mass moves into a region of warm
air.
Cold fronts affect the Caribbean region (especially the northern part of the region) during the
northern hemisphere winter. During this period, cold air from North America (Northers) moves
into the Caribbean. There is a well-defined boundary where this cold, dry air meets the warm,
moist air of the Caribbean. The cold air is denser and heavier and so it pushes its way beneath the
warm air. The warm air, which is lighter and less dense than the cold air, is forced to rise. The
rising of air will result in cooling. Cooling will result in condensation and then condensation will
result in cloud formation (cumulonimbus clouds). Eventually rain will fall (heavy rain and
thunderstorms). This is called FRONTAL RAINFALL.
How cold front affects the weather
- As the front passes the temperature may drop by several degrees (sometimes 50
C)
- As the font passes the wind speed increases
- Heavy rainfall along the line of the front and either side of it

123. Oral Johnson
- There is an increase in the amount of cloud with the development of particularly cumulonimbus
clouds
Cold Fronts affect the countries in the Northern Caribbean e.g. Jamaica, Bahamas Cuba and
Haiti
Cross section through a cold front
Symbol for cold fronts on weather maps

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Easterly waves
Among the most important rain producing system in the Caribbean are easterly waves. They are
also called tropical easterly waves or African easterly waves. These are areas of low pressure that
originate off the coast of West Africa. These are areas of low pressure that originate off the coast
of West Africa.
For much of the year, the trade winds which blow across the Caribbean bring dry, settled
conditions, but from time to time weather systems develop in the trade wind belt which bring
unsettled weather and rain. These weather systems develop more frequently in the rainy season,
from May to November. Tropical waves are one type of weather system. It is a wave-like
disturbance in the north-east trades and it may takes several days to pass over the region.

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127. Oral Johnson
Hurricanes
A hurricane is one of the most dangerous natural hazards to people and the environment. Every
year immense damage is done by tropical storms and hurricanes. Hurricanes are also known as
tropical cyclones in Asia. These storms are essential features of the Earth’s atmosphere, as they
transfer heat and energy between the Equator and the cooler regions towards the poles.
Some tropical waves travelling over the Atlantic become unstable and develop into hurricanes. A
hurricane is a tropical revolving storm. It is a very large circular area of low pressure, driven by
evaporation from warm seas. In areas away from the Equator, air is drawn into the hurricane to
replace the rising air. Owing to the Earth’s rotation, winds in a hurricane spiral inwards in an
anticlockwise direction. Wind speeds can reach 300 km/hour. The hurricane is driven by the
latent heat released as water vapour condensed into droplets.
Hurricanes form between latitudes 50
and 300
and initially move westward and slightly towards
the poles. Hurricanes don’t usually form close to the equator as the rotation of the earth (Coriolis
Effect) is not strong enough to cause the system to spin or spiral. An average hurricane can move
between 192km and 768km per day, and travel over 4000km before it dies out. Hurricanes are
measured using the Saffir-Simpson Scale. Hurricanes in the Atlantic occur between June and
November.
Several different factors are required to transform storms, which occur frequently, into rarer
hurricanes. These trigger mechanisms depend on several conditions being ‘right at the time’. The
most influential factors are:
 a source of very warm, moist air derived from tropical oceans with surface temperatures
greater than 260
C
 sufficient spin or twist from the rotating earth- this is related to latitude
As the warm sea heats the air above it, very warm most air rises up quickly, creating a center of
low pressure at the surface. Winds rush in towards this area of low pressure and the inward-
spiraling winds whirl upwards releasing heat and moisture. The rotation of the Earth causes the
rising column of air to twist. The rising air cools and produces towering cumulus and
cumulonimbus clouds. Further aloft at around 10km the cloud tops are carried outwards to create
a thick layer of clouds which mark the outward-spiraling winds as they leave the hurricane core.

128. Oral Johnson
The whole system may move slowly, at speeds of 15-20km/hour on average. Hurricanes start off
as very small areas of low pressure – often less than 10km in diameter. The eye itself can be up
to 40km wide.
Saffir-Simpson Scale
Structure of a Hurricane
A mature hurricane is roughly circular in shape and may be hundreds of miles across. The entire
feature rotates around a relatively calm center which is known as the eye of the hurricane. In the
northern hemisphere, hurricanes rotate in an anti-clockwise direction. Rain bands containing
massive cumulonimbus clouds spiral in toward the eye. These clouds form as a result of the
strong updraughts (rising air currents) within the hurricane. The rain bands are capable of
producing the very heavy rainfall associated with hurricanes. Some of the clouds tower up to a
height of 16km. Where the clouds are thickest, there is very little light, even at midday. At high
level, there is a canopy of cirrus clouds.
Strong winds spiral in towards the eye. Wind speed increases toward the center of the hurricane.
The strongest winds occur in a part of the hurricane which is known as the eyewall. The eyewall
is the part of the hurricane immediately surrounding the eye. Winds spiral into the eyewall and

129. Oral Johnson
then they spiral upward toward the top of the hurricane. At the top of the hurricane, winds spiral
outward.
At the center of a hurricane is the eye. The eye of a hurricane is the “hole” in the middle of the
hurricane. A typical hurricane has an eye which is about 20 – 40 miles (32 – 64km) across.
Conditions within the eye are relatively calm. Winds are light and there is little or no rain.
Within the eye, air is descending. The sky may be clear. As the eye of a hurricane passes over an
area, people who don’t know better may think the hurricane has passed.
Structure of a Hurricane

130. Oral Johnson
Description of the weather associated with a hurricane
Before
The approach of a hurricane is usually indicted by the appearance of feathery cirrus clouds at
great height. Then a veil of cloud appears across the sun, and the sky is bright red at dawn and at
sunset. The air is calm. Humidity is high, so the air feels hot and sticky.
During
As the hurricane gets closer there are occasional gusts of wind and showers of rain. During the
hurricane the wind speed is very strong and the rainfall is very heavy. To the west of the eye, the
wind blows from the north. The heavy rains can cause serious flooding and the heavy winds can
damage infrastructure. When the eye of the hurricane passes overhead, there will be a short
period of calm. After the eye has passed, the wind suddenly starts again. To the east of the eye,
it blows from the opposite direction- from the south. Heavy rain may continue for some time.
After

131. Oral Johnson
With the passage of the hurricane the winds gradually weaken, but steady rain can continue for
several days.
How Hurricanes die
Hurricanes derive their energy from warm tropical seas. They are weakened when they pass over
land. Even crossing an island the size of Jamaica will reduce the strength of a hurricane.
Some tropical storms and hurricanes lose their strength while they are still over warm tropical
seas in the Caribbean or Atlantic. This may happen when upper-level winds disrupt the outward
spiral of air above the hurricane.
Hurricane on weather maps

132. Oral Johnson
On weather maps hurricanes are represented by circular pattern of isobars with the lowest
pressure in the center (eye). The isobars are packed closely together and this tells us that winds
are likely to be strong.
Anticyclone
An anticyclone is a large area of high atmospheric pressure. Anticyclone may be thousands of
kilometers in diameter. In an anticyclone the air tends to sink or descend. As the air descends or
sinks, it is compressed and warmed (this means it can hold more moisture). These conditions are
not suitable for cloud formation and clearly is not a condition which favors rainfall. Therefore,
anticyclone are associated with long periods of sunshine or fair weather with few or no clouds
and no rainfall. Periods of fine settled weather are generally associated with anticyclones
Figure 8.8 shows that on weather maps anticyclones are represented by a roughly circular pattern
of isobars. The highest pressure is found in the middle of the anticyclone, and is lowest at the
edges. Winds move around the anticyclone in a clockwise direction in the northern hemisphere.
As indicated by the wide spacing of the contours in figure 8.8, differences in pressure are slight.
As a result, winds are very light.

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The Intertropical Convergence Zone (ITCZ)
The name Intertropical convergence zone (ITCZ) is given to the zone low of pressure which
occurs roughly at the equator. The North East Trade Winds, and the South East Trade Winds
blow from the sub-tropical high pressure belts and converge there. Where these two air masses
come into contact they force each other to rise. On rising the air is cooled, thus creating
conditions favorable for to rainfall.
The conditions which occur at the ITCZ depend to a great extent upon the angle at which the two
trade winds converge. If the angle is small, then only a limited amount of air rising takes place
and the weather is likely to be fine. But if the angle is large, a great deal of air rising occurs. This
results in the formation of a dense layer of cloud, and rainfall is likely to be heavy and
prolonged.
The ITCZ is not stationary, but moves slowly northwards and southwards. It follows with a lag
of 1-2 months the passage of the overhead sun. The sun is at its furthest position south on
December 22. At this time the ITCZ is moving southwards across coastal Guyana. December is
one of the wettest months in the coastal belt of Guyana. In the Caribbean region the ITCZ
reaches its most southerly position in February, when it is located over Southern Guyana (20
C).
It then starts to move back northwards again. The sun is at its furthest point north on June 21st
.
The ITCZ reaches its most northerly position in about August, when it is centered around
latitudes 100
N to 120
N. This helps to explain why Trinidad and Tobago gets a great deal of
rainfall at this time.
ITCZ- FROM NASA

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VEGETATION AND SOILS
What is an ecosystem?
An ecosystem is a community of plants and wildlife, together with the environment in which
they live. All parts of the ecosystem are interconnected. They affect each other in several
different ways. There are flows of energy and nutrient, and a change in one part of the ecosystem
will have effects on the other parts.
Being a system, an ecosystem is in balance, unless something happens to upset that balance.
People, as part of an ecosystem, are most likely to upset that system. A sudden physical change ,
such as natural disaster – for example a volcanic eruption or a hurricane- will upset the balance
for a while, but the system will recover in a surprisingly short time. The scale of ecosystems
varies hugely. An ecosystem can be something as small as a pond, an individual tree, a garden, a
beach or a field ; or it can be something much larger; a rainforest, a region of grassland , a whole
island. An ecosystem is a whole community, including plants, animals, insects, bacteria, climate,
soils, rock type and relief. Within the community plants and wildfire rely on each other. For
example, insects pollinate flowering plants and in return feed on the nectar- both are satisfied.
This relationship is called symbiosis. The species in an ecosystem change and develop over time.
They react to their circumstances and environment and adapt to them.
The earth’s surface can be divided into larger- scale ecosystems, each covering a huge area on
the land surface. These larger systems are called biomes. Each biome takes its name from its
dominant type of vegetation. Examples include rainforest, savanna, temperate deciduous
woodland, tundra and desert.

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How does an ecosystem function?
Components and functions of an Ecosystem
An ecosystem is made up of living and non-living components
Living (biotic) components: This includes all organisms in an ecosystem including plants and
animals from the very large to the microscopic. The living components of an ecosystem can be
further subdivided into the following groups:
 Producers: Producers are the green plants and they are the basis for the other living parts of
the ecosystem. Ecosystems receive their energy from the sun. Solar radiation (the sun’s
energy) enters the atmosphere and is absorbed by chlorophyll in leaves. The process of
photosynthesis then takes place. In simpler terms, they use carbon dioxide, water and
sunlight to make food. The energy created from these processes then flows through the rest
of the system. This is the called the food chain. It is the series of events where one species
eats another. Each level of plants or animals becomes the food for the species above it in the
system. There are many types of producers, from the largest trees in the rainforest to
microscopic algae. All other organisms in an ecosystem are dependent on producers either
directly or indirectly.

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 Primary consumers: These are organisms (birds, insects) which obtain their nutrients
directly from plants. They are also known as herbivores. Examples of primary consumers
include grasshoppers, goats, parrots, monkeys, tapirs and zebras.
 Secondary consumers: Carnivores are meat eaters and so they feed on the herbivores or on
other, smaller carnivores. Usually those that eat other carnivores are the larger species and
are known as the higher carnivores; these include the big cats like jaguars, lions and
cheetahs. Lizards, spiders and eagles are examples of lower carnivores.
 Decomposers: Another part of the food chain which cannot be ignored is the decomposers.
Decomposers are bacteria and fungi which rot down dead plant and animal material. They
make the nutrients in these materials available to the next generation of plants. Small soil
fauna (animals and insects) work as an important part of the system too. Once dead plants
and animals are rotted down (decomposed) by the decomposers their remains are mixed into
the soil by earthworms and ants. The material is called humus and it is packed with
nutrients that will feed the next generation of plants. In this way the whole cycle or system
is completed.

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Non-living (abiotic) components: These components include sunlight, temperature, water and
soil. These components play an important role in determining the types of ecosystems which
develop in particular areas. Inputs add nutrients, water or energy to the system. The main ones
are rainwater, sunshine and minerals. The sun’s energy, which gives the whole system its
energy. Rainfall, which is important in two ways:
- It adds a few nutrients to the system, minerals which are dissolved in the rain water
- The water itself is essential for plant growth and for animal life
All systems have inputs, processes and outputs. The outputs are losses of water and nutrients
from the system. Some rain falling on the ground trickles through the litter and is lost (runoff).
As it passes through the litter it dissolves some nutrients, so they are also lost from the system.
Water that reaches the soil may also be lost, deeper underground, again taking nutrients with it.
Climate, Soil and Ecosystems
Ecosystems are influenced by thefollowingfactors:
Climate:
Climate plays a major role in determining the type of ecosystem which develops in an area. Plant
growth is encouraged where there is a warm climate, withhigh rainfall all year round, as in a rainforest.
When plants grow rapidly, thereis plentyof food for primaryconsumers; these in turn become food forthe
secondaryconsumers. The amount of rainfall experienced annually in an area will affect the types
of plants and animals which can survive there. For instance, in an area which experiences very

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little rainfall, you will only find plants and animals which are able to survive in the dry
conditions. Temperature is also an important factor in determining the type of ecosystem which
develops in an area. In areas which are very cold you will find plants and animals which are
adapted to survive in low temperatures. Similarly, in areas which are very hot you will find
organisms which are adapted to survive in high temperatures. Therefore, when studying an
ecosystem, it is important to acknowledge the influence of the climate.
Soil
Soil often plays a major role in the development of an ecosystem. Soil is composed of weathered
material, organic matter, water and air. There are many types of soil. The type of soil which is
found in an area is influenced greatly by the climate and also the type of rock which is weathered
to produce the soil. The type of soil found in an area determines to a large extent the types of
plants which can grow there. This in turn influences the types of animals which can survive
there.

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Tropical Biomes
The zone of the Earth between the Tropic of Cancer (23.50
N) and the Tropic of Capricorn
(23.50
S) is known as the tropics. Within these latitudes is a huge variety of different biomes and
ecosystems. These include
 Equatorial rainforest
 Tropical marine
 Tropical continental
 Hot desert
 Semi-desert
The first two in the list will be looked at in detail
Equatorial rainforest
Latitude/ location: Equatorial rainforest is the most productive ecosystem in the world. Over
40% of the world’s plant and animal species come from the rainforest, yet it only covers just
over 5% of the land surface. The most dense equatorial rainforest is found between 100
N and
100
S of the Equator. Similar ecosystems thrive on either side of this zone and are generally
referred to as tropical rainforest. The main regions are:
 Parts of the Caribbean-southern Cuba, much of Hispaniola, northern Puerto Rico,
Trinidad
 Central America
 The Amazon Basin
 Coastal West Africa (although much has now been cleared for urban development)
 Central Africa- the Congo Basin
 South-east Asia- Malaysia, Indonesia
 Australia- the northern tips of the country.

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Climate: Constant high temperatures and regular rainfall are typical of the equatorial climate.
The temperatures are high all year round with little to no variation from month to month. In fact
the rainforest has one of0
the lowest annual temperature range out of all the ecosystems that
exists on earth. This is approximately 30
C. A true Equatorial total is 2000mm or more per a year.
Rainforest vegetation
The most obvious characteristic of rainforest vegetation is its layering. Tall trees are common in
rainforest- it is well known for this. Underneath these, however, are several other vegetation
types. From sky to the forest floor these are:
 Emergents- the very tallest trees, which are around 50m in high and grow above all other
vegetation.
 Canopy- The main mass of tall trees, about 40m tall. They formed a closed ‘top’ to the
forest; in other words, if you were flying over it you would see continuous treetops and
no ground at all. Much wildlife lives in this layer, and rarely leaves the relative safety of
the trees: most birds, mammals like sloths and many species of monkey.
 Lower tree layer- this is made up of younger trees which will eventually become part of
the canopy, plus mature trees of smaller species, such as palms (about 15-20m tall).
 Shrub layer- bushes up to 5-10m high. Only 1% of the sunlight received at the canopy
penetrates to this depth, so there is little photosynthesis and plant growth is slow.
 Ground layer- shade- loving plants which are usually less than 1 meter in height. They do
not cover the whole ground surface because few plants can cope with this degree of
shade. Bare ground, with lots of litter, is common the rainforest floor. Wildlife here eats
fruit and seeds from the litter.
Characteristics and adaptations of rainforest plants
The trees and plants of the rainforest have adapted to their environment.
 Trees have slender trunks with thin, smooth bark to help them shed heavy rain. There is
no frost, so no extra protection, such as thick bark is needed.
 Trees are tall and the canopy is wide to reach maximum sunlight for photosynthesis

143. Oral Johnson
 Their roots are at the based, called buttress roots, are especially wide to help support this
great height. Extra roots, or radicles, grow down from branches to make the trees more
stable.
 Leaves have drip tips, with curved ends, which help them shed excess rain water easily.
They are leathery to protect them from the sun
 Many trees are tall and have relatively straight tree trunks. The branches and leaves are
concentrated near to the very top of the tree to maximize the amount of sunlight they
receive. Having leaves on the lower parts of the trunk will not be very useful as very little
sunlight will reach them.
 Some plants in the lower layers of the rainforest have very large leaves in order to make
efficient use of the little sunlight that reaches them.
 Some plants, known as Lianas, are veins which are rooted in the soil and grow up the
trunks of trees all the way into the canopy where their leaves can get more sunlight.
 Epiphytes are plants that used dead material which has collected in the forks of trees, for
example, as a place in which to root rather than in the soil. They simply use the tree for
support but derive no nourishment from the tree itself.

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Tropical marine biome
Latitude
This biome is found between 100
and 20o
North and South of the Equator. These latitudes in the
northern hemisphere coincide with much of the Caribbean. As its name suggests, the sea is the
most important influence on the climate here. The islands on the eastern edge of the Caribbean
region experience this climate: The Bahamas, Antigua, Dominica, St Lucia, Barbados, Grenada
and Tobago.
Climate

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The trade winds blow all year in these latitudes. These are warm winds that pick up lots of
moisture over the ocean. Two seasons can be identified: a drier season from January to May and
a wetter one between June and December. Figure 8.23 shows climate data for the lowland parts
of Grenada, and this seasonal difference is clear on the rainfall graph. The wetter season is also
slightly warmer. There is no clear division between the seasons. Temperature and rainfall both
rise and fall gradually. Although the drier season is dominated by high pressure systems, some
rain occurs every month. The main difference between equatorial and tropical marine climates is
the rainfall pattern; temperatures are similar.
Ecosystems
There are five main ecosystems within the tropical marine biome, classified according to the
amount of water available: rainforest, mangroves, mesophytic and xerophytic woodland. The
wettest areas can sustain rainforest as described above. Some coastal strips have mangroves, for
example in Grenada.
Semi- evergreen forest is a mesophytic ecosystem, meaning that it needs quite a lot of rain but
can survive a short dry season. There are fewer trees and they are not as tall as in the true

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rainforest. Some are deciduous, shedding their leaves annually to save moisture. Smaller leaves
also help here. Litter is an important nutrient store in this ecosystem.
Dry woodland is a xerophytic, or drought-resistant ecosystem. It is found in the driest areas,
usually because they are in a rain shadow area. Less moisture means:
 Smaller plants- trees are rarely taller than 25m
 Bark is thicker to help keep moisture in
 Trees are deciduous and/or have small leaves
 Growth is limited- the whole system, both plants and animals, produces less biomass
 The amount of litter limits the growth of ground-cover plants
 Biodiversity is lower than in the other ecosystems- that is, there are fewer species
Much dry woodland has been cleared for farming but this was not always successful. Today
many areas have scrub vegetation which includes cacti and succulents, plants which are truly
xerophytic.

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Soil and soil profiles
The soil is an important part of any ecosystem. Soil directly affects vegetation and wildlife. In
turn they affect the soil, and so do the bedrock underneath it and the climate above it.
Soil formation
Soil is formed from two different sources:
 The bedrock provides the mineral material
 The vegetation provides the organic material
Climate is also an essential factor in soil formation. Bedrocks breaks down by weathering into
smaller fragments called regolith. This happens particularly in tropical regions of the world such
as the Caribbean because of high temperatures and plentiful rainfall. Chemical reactions that help
to weather rock happen much more quickly in warm wet conditions. Tropical soils are therefore
the deepest in the world, up to 30 meters deep.
As soil develops vegetation takes a hold. When plants die they become part of the litter layer,
where they are broken down by decomposers to form humus. This dark brown/blackish organic
material is mixed into the mineral part of the soil by small animals and insects (soil fauna) such
as earthworms. Organic material and mineral material together forms soil particles, or crumbs,
and between these is air and water, which also make up a very important part of soil. Figure 8.5
shows the approximate proportions of all four parts of soil.

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Other factors affect the characteristics of soil. Slope is important. Thicker soils form on flat land
or gentle slopes. On steeper land the soil particles move downhill under the force of gravity, so
the steeper the slope, the thinner the soil. Another factor that is easily forgotten is time. Soil
needs time to form, usually thousands of years. The longer they have been developing, the
thicker they are, although each soil type has it maximum depth. The warmer and wetter the
climate, the less time it takes to form a mature soil.
Soil profile
The soil profile is a section down through a soil from the surface to the underlying bedrock. In a
mature soil, the profile usually consists of successive layers, which are called horizons. The O
horizon is mostly organic matter such as decomposing leaves at the surface of the soil. It is also
called the humus layer. The A and the B horizons represent the true soil, while the C horizon is
the subsoil or weathered parent material. The D horizon consists of unweathered bedrock.
Different soil profiles are found under different conditions, and soils are recognized and
classified on the basis of the parts of the profile which are present.

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Tropical soils
Tropical soils are very much influenced by their climate and these are called zonal soils. There
are also intrazonal soils, where local factors such as rock type are more important. Tropical red
earths are zonal soils and these cover a large area of the tropics, especially under rainforest.
Latosols/ Tropical red earths
Latosols are found in areas which have a hot, wet climate throughout the year, often where the
natural vegetation is tropical rainforest.
Factors influencing the formation of latosols
Climate
 Latosols form in very hot and wet conditions in the tropics and equatorial regions. High
rainfall and temperature causes rapid chemical weathering. The soil is of great depth due
to rapid weathering of the underlying rock. Latosols are therefore the deepest in the
world, up to 30m deep.
 Precipitation exceeds evaporation in this environment, therefore leaching takes place.
There is so much rain in the tropical rainforest that minerals are quickly dissolved and

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washed down into the lower soil. If plants do not absorb the nutrients quickly, rainfall
will bring it to lower levels where it is inaccessible to plants and the soil becomes acidic.
Leaching is intense, only iron and aluminum compounds (oxides) remain and this gives
the soil its red colour.
Soil Biota
The soil organisms are greater and more active due to the warm and wet conditions.
Decomposition of organic matter by microorganisms such as bacteria and fungi are very rapid in
this ecosystem.
Vegetation
The tropical rainforest is a very dense and evergreen ecosystem. Vegetation is in abundance and
is very diverse. This suggests that they are rich soils- otherwise how could they support
rainforest? However, this is not really true! Certainly tropical red earths/latosols support
rainforest, but they are quite poor quality soils, because of the very rapid recycling nutrients
within the ecosystem. As soon as plants shed their leaves, they rot down and become humus. Soil
fauna mix this into the soil very quickly, and plants take up the nutrients almost immediately.
The cycling of nutrients in the rainforest system is the fastest in the world.
When rainforest trees are cut down and the land is used for farming, there are few nutrients in the
soil. They are used up very quickly and there is little litter to help replace them. The nutrients
cycle of the ecosystem has therefore been destroyed, because most of the nutrients were held in
the trees, not in the soil. The structure of the soil is damaged and it erodes away easily.

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Impact of humans on the rainforest
One hectare (10,000m2
) of rainforest is destroyed by people every second- this is the equivalent
of two American football fields- but even more shocking, means that an area larger than New
York City is devastated every day. That equates to the area of a country the size of Poland every
year.
Causes of deforestation
Slash and Burn
Traditional rainforest people grow crops using the system of shifting cultivation or slash and
burn. This involves extended family groups of over 30 individuals clearing undergrowth, cutting
down large trees and burning them, then spreading the ash as fertilizer. Such ground can be
farmed for two to three years with up to three annual crops before the soil is exhausted of
nutrients and needs time to recuperate (fallow periods). Clearings are small enough that heavy
ran does not erode the soil. A single group operates a few clearings at a time and then moves on
to new ones, ideally returning to past lands after 30 years, by this time the soil should be returned
to full fertility. Slash and burn is sustainable as long as it does not become intensive.
 Population increase in West Africa caused plots to be cleared too close to each other,
opening up the forest and allowing rain to cause soil erosion. Fallow periods became
shortened so soil was not able to regain full fertility, making it lose its structure and be
more vulnerable to erosion. Serious forest destruction was the result, leaving people with
no land to form, many were therefore forced to migrate to urban areas to try to earn a
living.
 New transport routes through the rainforest, in particular the Trans-Amazon Highway,
have let new settlers from poverty-stricken Brazil into the rainforest to try to earn a living
through slash and burn. Lack of traditional skills has led to people failing to produce, and
much rainforest destruction.
The Timber industry
Commercial logging is the major cause of deforestation today in Southeast Asia and Africa. In
Amazonia there has been a greater pressure to cut timber sustainably, taking the high value trees

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without destroying everything else around them. Demand from the developed world drives the
market in tropical hardwood timber- without that the business would not be so destructive.
Indonesian rainforest has suffered harshly as the country strived to develop by exporting high
value goods to the more developed world. There is still lack of understanding in North America
and Europe over the environmental consequence of rainforest destruction.
Cattle ranch and Soya Bean production
Ranching has been a huge cause of rainforest deforestation, being responsible for 80% of tree
cutting in all Amazonian countries (Brazil, Peru, and Bolivia) in the early years of the 21st
century. Cattle-ranching is an extensive system of farming, using a whole hectare of cleared
forest for every animal.
Demand from the western world for meet has been important, but today the large rapidly
developing countries like China and India have growing middle class who demand diet that
represents a high standard of living with lots of protein. Carbon emissions from clearance for
ranching caused 3.4% of global output in 2008. Global companies like McDonald have caused
significant rainforest damage and have received public condemnation for this e.g. public pressure
has caused them to change their policy. By 2006 McDonalds claimed to have stopped clearing
rainforest for cattle and no longer bought soya beans grown on cleared forest ground for cattle
feed.
Nevertheless, soya grown on cleared Amazonian rainforest is increasingly used to feed cattle and
chickens. Brazil, the second largest soya producer, exports to the USA, Europe and China, who
produce beef and poultry for other fast-food restaurants and people’s dinner tables. An area the
size of the US state of Vermont has been cleared for soya production in the Brazilian state of
Mato Grosso Alone.
Hydro-electric Power (HEP)
An unlimited supply of water on the Parana River feeds Itaipu, on the Brazil/Paraguay border,
said to be the largest HEP system in the world, ahead of the Three Georges Dam in China. It
supplies electricity for Brazil largest city, Sao Paulo, with its population over 21 million and
expanding industries. In order to create the reservoir behind the dam, 2430km2
of rainforest has
to be flooded, threating several mammal species and whole ecosystems. Brazil is an NIC (newly

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industrializing country) whose economy is growing rapidly on the back of such infrastructural
developments.
Soil exhaustion and erosion
Tree roots anchor the soil, preventing erosion, but when trees are gone the soil has little
protection from the heavy rains. Widespread soil erosion has occurred, and is still occurring
throughout the tropics as a result of rainforest clearance. The consequence include:
 Soil loss across tropical regions has been immense, and continues.
Costa Rica loses about 860 million tonnes of valuable top soil every year. Most of this is washed
into rivers and then into the sea. Madagascar loses more soil more than everywhere else- 400
tonnes per hectare per year turning rivers red and staining the sea far out into the Indian Ocean.
Astronauts looking back towards the Earth have said that Madagascar looks as it is bleeding to
death.
 Crop yields decline and people must spend their limited income on expensive imported
chemical fertilizers in order to produce an adequate crop.
 Offshore coral reefs are being suffocated by soil which is washed into the sea. Coastal
fisheries suffer not only from loss of coral reefs but also the silting up of mangrove
swamps.
Sustainable Management
The Forest Stewardship Council (FSC) is an international organization which aims to increase
the proportion of timber and other rainforest resources that are obtained sustainably. It aims to
reduce the demand for rare, valuable tropical hardwoods through educating people of the
consequences of such unsustainable exploitation. Products that have been sourced from
sustainably managed forest have the FSC label.

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NATURAL HAZARDS
Natural hazards involve hydrological, atmospheric and geological events. A natural hazard is a
natural event that causes damage to property to cause damage to property and/or disruption to
normal life, and it may cause loss of life. A hazard refers to a potentially dangerous event or
process. It becomes a disaster when it affects people and their property.
Hazards in the Caribbean
Some groups of people are more vulnerable to natural hazards and have greater exposure to
them. Exposure to hazards varies over time and by place. Some locations are more hazardous
than others. The Greater Antilles, for example, has no active volcano but in the Lesser Antilles,
Soufriere Hills in Montserrat and Kick ‘em Jenny, off Grenada, are both currently active. Coastal
areas tend to be more vulnerable to coastal surges while upland areas, such as Upper St Andrew
in Jamaica, are at greater risks of landslides. Some cities, such as Kingston in Jamaica, are
subject to various hazards, such as earthquakes (1692, 1907 and 1993), landslides ( 1963 and
1988), hurricanes ( Charlie 1951 and Gilbert 1988) and coastal flooding. Caribbean countries are
vulnerable to natural hazard because:
 they are close to plate boundaries, risk zones for earthquakes and volcanic eruptions;
 they have hurricanes and intense rainfall;

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 most people live close to the sea;
 many people live on steep slopes subject to landslides, or on flat land close to sea level;
 humans greatly altered the Caribbean environment, e.g. forests and coastal mangroves
have been removed.
Why disaster is increasing
Since the 1950s, damage from natural disasters has increased worldwide, because:
 with economic development, more buildings, roads, industrial plants, airports, and other
structures have been constructed;
 people build in hazardous places- shorelines, steep hillsides, or flat land with a flood risk;
 most scientist believe that climatic change is increasing the risk of extreme events, such
as floods, droughts and hurricanes.

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In 2003, an estimated 700 natural catastrophes worldwide killed more than 50,000 people, and
caused US$ 60 billion in damage.
Impact of Hazards
Volcanoes
Lava flows - A river of molten rock 1000 degrees centigrade that can travel at 40mph. lava flows
can cause extensive damage or total destruction by burning, crushing, or burying everything in
their paths. Lava flows can erupt relatively non-explosively and move very slowly (a few meters
to a few hundred meters per hour) or they can move rapidly (typically down steep slopes.
Tephra - All materials ejected from a volcano are called Tephra. These occurs when there is an
explosive eruption. They are classified according to their sizes. Materials the sizes of a football
can be ejected from a volcano. Ash, lapilli and volcanic bombs are tephra. The largest pieces of

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tephra (greater than 64 mm) are called blocks and bombs often fall close to the volcano but
smaller size tephra such as ash and lapilli ( lapilli 2-64 mm) and ash (<2 mm) can be carried
downwind and affect areas far from the volcano. Millions of tons of ash can bury buildings.
Problems associated with tephra
- If ash builds up on the tops of roofs, it will often cause collapse. This is especially
common on flat topped buildings. Most deaths resulting from the eruption of Mount
Pinatubo in 1991 were due to collapsing roofs (Wolfe, 1992).
-Ash can disrupt electricity, television, radio, and telephone communication lines, bury
roads and other manmade structures, damage machinery, start fires, and clog drainage
and sewage systems
Ash is also a great hazard to airplanes. Ash from the 1982 eruption of Galunggung
Volcano in West Java, Indonesia caused engines in two jet airplanes to fail. Both aircraft
dropped 25,000 feet before they could get their engines to start again.
-Tephra can also destroy vegetation which can result in famine. Famines are the largest
indirect hazard produced by volcanic eruptions. In 1815, after the eruption of Tambora
which ejected 151 cubic kilometers of ash into the atmosphere, 80,000 people died due to
famine (Bryant, 1991 and Francis, 1993)
-Ash can produce poor visibility and cause respiratory problems.
Pyroclastic flows - Pyroclastic flows are very hot, fast moving clouds of gases and
tephra moving down the side of a volcano after an eruption column collapse. They are
also called nuée ardentes. They are extremely dangerous because they can travel up to
500 km/hr, reach distances of 30km and can be over 700 degrees Celsius in temperature.
They will burn, knock over or bury anything in their path. A pyroclastic flow from
Vesuvius volcano killed about 20,000 people in Pompeii in 79 CE.
Lahars ( resembles wet concrete) -A volcanic eruption usually leaves lots of loose

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unconsolidated fragmental debris. When this loose material mixes with water from
rainfall, melting of snow or ice, or draining of a crater lake, a mudflow results. Volcanic
mudflows are called lahars. These can occur accompanying an eruption or occur long
after an eruption. Lahars are very dangerous because they do not require a volcanic
eruption yet can travel hundreds of miles. All that is required is loose pyroclastic material
on the volcano that mixes with precipitation or melting snow.
In general, they destroy anything in their path, carrying away homes, buildings, bridges,
and destroying roads, and killing livestock and people.
Hurricanes
Wind damage
Hurricane winds have great physical strength. A 40% increase in wind speed doubles its
destructive power, a 140km/h wind is twice as powerful as a 100km/h wind.
 Even a moderate wind can damage crops such as bananas.
 Winds blow down trees, which can crush buildings or block roads.
 Winds topple utility poles. Where electricity and telephone lines are down, it may take
weeks or months to restore services. Masts which transmit cellular calls may also be out
of action.

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 Roofs are vulnerable. Near the eye of a powerful hurricane, most roofs are torn off; some
are damaged even in a tropical storm.
 Flying debris, such as coconuts or sheets of roofing material, may kill or injure people
and cause further damage to buildings.
 Strong winds can demolish walls, particularly those in poor repair or with no reinforcing
steel bars.
Storm Surge
Near the eye of a major hurricane, sea levels are several meters above normal. Low atmospheric
pressure allows the water to rise. The storm surge is strengthened as it approaches the shore, and
low-lying coastal areas are flooded. Combined with strong winds and heavy rains, the effect is
devastating.
Flooding
Hurricanes bring heavy rain over a wide area, up to a quarter or a third of average annual rainfall.
During a hurricane in 1909, more than 2,400mm of rain fell over four days at Silver Hill in
Jamaica. Intense rainfall in a short period causes flooding.
 In flash floods, a torrent rushes down a river valley or narrow gully. The power of the
flood may knock down buildings, wash away cars, or drown those in its path.
 On flat land, wide areas can be flooded by slowly rising water. Furniture may be ruined,
vehicles damaged, and crops destroyed. Floodwater also threatens diseases, by spreading
sewage and animal waste into the drinking water.
Landslides
When Hurricane Mitch devastated Honduras and Nicaragua in 1998, most of the damage came
from landslides, which killed 9000 people. Up to 500, 000 people were left homeless. Landslides
are triggered where steep hillsides are sodden after heavy rain, which increases the weight of the
soil and rock; and lubricates the soil and rock particles, so that they can move more easily. The

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danger of landslides is increased where stabilizing forest cover is removed, or where a hillside
has been steepened by excavation, for example to construct road.
Wave damage
Waves may reach 8 meters high (24 ft). There may be severe beach erosion. Marine life can be
damaged, and coral broken and killed. In Belize, lobster and conch fisheries took at least a year
to recover after hurricane Iris.
Coastal structures can be torn down. Hurricane Lenny in 1999 came from the west, battering the
sheltered leeward coast of the eastern Caribbean islands, and damaging ports, boats, coastal
roads, and hotels. In St Kitts, a new cruise ship facility, Port Zante, had to be rebuilt.
Ships and boats are at risk, whether they stay in a sheltered harbour, or choose to ride out a
hurricane at sea. In the seas off Belize, an 85- meter cruise ship, the Fantome, disappeared in
1998 during hurricane Mitch. The crew of thirty were killed; the 100 passengers had been left on
shore. During Hurricane Iris, seventeen passengers and three crew were killed when a dive boat
capsized in port; they had not gone to a hurricane shelter.
Earthquakes
In the Caribbean, major earthquakes are less common than hurricane, but they can cause
devastation and strike without warning. These are the main dangers:
 Tremors- The ground vibrates during an earthquake. Push waves travel outwards from
the focus of the earthquake, and shake waves travel from side to side. Walls may crack,
and windows may break. Some buildings could collapse under the strain. Utility poles
may fall leaving live wires exposed.
 Ground fissures- in a powerful earthquake, the ground splits and cracks.
 Liquefaction- Reclaimed land or loose sediments which are saturated with water may
behave like a liquid during an earthquake. Buildings may sink into the ground, or
overturn.

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 Landslides- Landslides may be triggered on steep slopes, particularly if the ground is
already wet or unstable.
 Floods- Earthquakes may burst a dam, with a rush or raging water down the valley
below.
 Fires- In earthquakes such as Tokyo in 1923 and San Francisco in 1906, cooking fires set
wooden buildings alight. This caused more damage than the earthquake itself. Pipes
which carry gas may burst, adding to the danger.
 Tsunamis- a powerful submarine thrust-fault earthquake of magnitude 7.0 or more can
produce a giant wave or tsunami, devastating low-lying coastal regions.

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Individual, National and Regional responses to hazards
Individual measures/approaches to reduce the impact of hurricanes
- To limit damage to houses, owners are now encouraged to fix hurricane straps to roof and
put storm shutters over windows. Permanent shutters are the best protection. A lower cost
alternative is to put up plywood panels)
- Build houses with reinforced concrete ( concrete with steel rods to give added support)
- Houses along the coast can be built on stilts so they allow flood waters to pass away
safely
- Trim tree branches away from your home and cut off all dead or weak branches on any
trees on your property
- Avoid building homes/houses such as steep slopes or near to river banks ( or the edges of
river banks)
- Ensure that assets e.g. houses and cars are insured. Ensure that policies are valid and
coverage is appropriate
- If a hazard seems imminent (e.g. when a hurricane warning is given) evacuate your
homes especially if you are living in highly vulnerable areas. E.g. on low lying areas that
are at risk from flooding
- Make sure you have disaster supplies on hand such as : first aid kit, non-perishable
(canned food) and water, flash light and extra batteries, portable battery operated radio
and extra batteries, essential medicines
- Develop and emergency communication plan-make sure all family members know what
to do. Teach family members how and when to turn off gas, electricity and water.
- Know your emergency shelter-contact the national disaster office for your closest shelter.
National measures to reduce the impact of hurricanes
National governments and local agencies can help to prepare for a hurricane in a number of ways
- Land use zoning- hurricane damage tends to be focused on low lying coastal areas and
alongside rivers where flooding is a major hazard. National governments can devise land
use plans so to keep vulnerable groups and expensive land uses away from these areas. The

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most important facilities are placed in the least vulnerable areas and the least important
facilities in the more vulnerable areas
- Building regulations- new buildings can be constructed with strong walls, doors, windows
and roofs to withstand strong winds ( wind and water resistant)
- Communications- communication and utility lines for example telephone and utility lines
should be located away from the coastal area or installed underground
- Planting trees and other vegetation helps to reduce the impact of soil erosion and landslides
and enables the absorption of rainfall, which in turn helps to reduce flooding. In addition
mangrove trees can be planted along coastal areas to help t break up the power of waves
and reduce the impact of storm surges.
- Create hazard maps- hazard maps can be used to provide information that can influence
people’s behavior and reduce their vulnerability to natural hazards such as flooding,
landslides and volcanic eruptions.
Based on historic events and scientific surveys, zones of different levels of risk can be
identified, Governments may decide to restrict developments in high risk zones or devise
detailed evacuation plans. By identifying the areas at greatest risk, actions can be taken to
reduce the likely impact of an event
OFFICE OF THE DISASTER PREPAREDNESS AND EMERGENCY MANAGEMENT
Jamaica has been severely affected by natural hazards, particularly flooding associated with
hurricanes. Established in 1973, this permanent disaster management organization is committed
to preventing or reducing the impacts of natural hazards in Jamaica
Some of the measures used by the ODPEM to reduce the impact of disaster:
 Public education- The ODPEM believes that public education is key in hazard
management. There is public website that educates the citizens on the various hazards
that affect the country. There is a public website also dedicated to children. In addition
information also includes response tips for each hazard. Information is also shared via
radio, television, newspapers and social media. If people know how to prepare and
respond to hazards, this can reduce the damage and loss associated with disasters.

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 Implementation of activities in public organizations -The ODPEM also implement
awareness programs in schools and other organizations. There is an annual earthquake
drill program organized by the ODPEM and the education ministry. This initiative
prepares students to function effectively when they are impacted by a major earthquake.
 Relocation of people in high risk zones- There was a law that was passed in 2015 that
gives the ODPEM the power to relocate persons in high risk areas if certain hazards such
as flooding are imminent. In some cases residents are sometimes reluctant and adamant
that they’re not moving.
 Establishment of disaster shelters- The establishment of disaster shelters also helps to
reduce possible injuries or deaths. Most communities are assigned a disaster shelter or
shelters, this is usually a church or school). Before a major hurricane people who reside
in high risk areas (e.g. flood prone) are move to shelters. There is approximately 900
shelter across Jamaica that are usually inspected before each hurricane season. Each
shelter is provided with relief supplies.
 Coordination of pre and post-disaster activities- Poorly kept and maintained drains are
sometimes the major causes of flooding. Some the gullies in Kingston are clogged with
debris and garbage. The ODPEM along with the local government conduct drainage/gully
cleaning activities on a timely basis to ensure the proper maintenance of the gullies. The
ODPEM also helps with clean-up activities after major hazards
 Establishment of flood warning systems- In some communities there are flood warning
systems. Rain gauges are located in rivers which collect precipitation data. This
information is then processes by a computer which can tell the likelihood of a flood. This
information is then pass on to residents of a community to evacuate if a flood is
imminent. A flood warning system was recently installed in fellowship, Portland (Nov
2018) to help community with flood related disasters.
 Development of disaster management plans and establishment of parish disaster
management plans and establishment of parish disaster committees to coordinate
activities at the local level- ODPEM also coordinates activities at the parish and
community levels. At the parish level, ODPEM works through Parish disaster
committees, which operate out of the Parish Council offices. These parish Disaster
committees are responsible for disaster management activities at the parish level.

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INDIVUAL AND NATIONAL RESPONSES TO FLOODING
INDIVIDUAL MEASURES
 Make sure you have a battery-operated radio with extra batteries. Follow all instructions.
If told to evacuate move out of the house or building to a safe, high ground.
 Turn off all utilities at main switch if evacuation is necessary. Do not touch any electrical
equipment unless it is in a dry area or you are standing on piece of dry wood with rubber
footwear and gloves.
 Remove all valuables. Wrap all important personal items, family documents electrical
appliances, pictures and wall hangings in plastic bags.
 Avoid already flooded areas. Do not attempt to cross any stretch of floodwaters on foot if
water is above your knees.
 Cars can become coffins in floods. DO NOT drive where water is over roads as under
those floodwaters the road could already be washed away and rapidly rising water could
lift the car and carry it away.
 Do not go sightseeing in flooded areas.
 If caught in a house by suddenly rising water move to second floor and or if necessary, to
the roof. Take warm clothing and a flashlight with you - as well as battery radio. Wait for
help.
NATIONAL/GOVERNMENT MEASURES
 Flood warning systems - In some communities there are flood warning systems. Rain
gauges are located in rivers which collect precipitation data. This information is then
processes by a computer which can tell the likelihood of a flood. This information is then
pass on to residents of a community to evacuate if a flood is imminent. A flood warning
system was recently installed in fellowship, Portland (Nov 2018) to help community with
flood related disasters.
 Some technical approaches have been used in the Caribbean including check dams,
gabion baskets, levees and paved drains
- Check dams- these are small dams usually formed of rock or timber that are built
across small channels and gullies to slow down the flow of water
- Gabions- wire cages filled with rocks can help to support and strengthen river
banks

166. Oral Johnson
- Levees- raised river embankments that can increase the capacity of a river
channel, making flooding of adjacent land less likely
- Paved drains- wide and deep paved drains are common sights alongside roads in
towns. While these may be dry for most of the year, they are capable of
containing large volumes of water during heavy rainstorms.
 Some countries such as Grenada and St Lucia have flood hazard maps. Hazard maps
prevent development in areas that are at high risk of flooding.
 Poorly kept and maintained drains are sometimes the major causes of flooding. Some the
gullies in Kingston are clogged with debris and garbage. The ODPEM along with the
local government conduct drainage/gully cleaning activities on a timely basis to ensure
the proper maintenance of the gullies. The ODPEM also helps with clean-up activities
after major hazards
INDIVUAL AND NATIONAL RESPONSES TO EARTHQUAKES
Especially in small earthquakes, which make up the vast majority of all earthquakes, most
injuries and fatalities occur because the ground shaking dislodges loose objects in and on
buildings.
INDIVIDUAL RESPONSES
 What-nots, wardrobes, freestanding closets, dressers and bookcases: these may topple
over during an earthquake unless they are securely anchored to the wall. These can be
bolted directly through the back of the furniture into the wall
 Hanging plants: these tend to swing widely during earthquakes. Use lightweight,
plastic containers or baskets instead of heavy, ceramic ones that may cause serious
injuries if they strike someone in the head
 Mirrors on walls: ensure that mirrors are securely bolted to walls.
 Heavy objects on wall shelves: ensure that shelves are securely bolted to walls.
 Hanging lamps or chandeliers: make sure they are securely fastened to the ceiling.
Put a mesh or plastic guard around fluorescent bulbs to catch any splinters.
 Install proper latches on cupboard doors that will not open if the object tilts over or is
shaken. Heavy objects inside your cupboards can lean or fall against the inside of the

167. Oral Johnson
doors, so the latches must be strong enough to withstand this pushing. Be careful not
to stand directly in front of cupboards as items lying against the doors can come
crashing out on you.
 The primary hazard in the bathroom during an earthquake is broken glass. Mirrors,
toiletries, and medicines can fall and break. Most personal care products are now
being packaged, but liquid medicines, perfumes and colognes are sometimes supplied
in glass containers. Select products in unbreakable containers where possible and
make sure the doors of your medicine cabinet can be secured with a latch.
 Gas stoves with rigid feed lines: use flexible gas lines that will not break during an
earthquake and release gas. Anchor the gas cylinder to the wall with chains and if you
are cooking, turn off the stove before taking cover.
 House not bolted to foundation: ensure that houses/buildings are properly attached to
their foundations.
 Make sure you have a fire extinguisher, first air kid, a battery-powered operated radio
and extra batteries at home.
 Learn how to turn off, gas water and electricity
NATIONAL RESPONSE TO EARTHQUAKES
Earthquakes are unpredictable hazards. Even through different models have been develop none is
yet to tell the exact time and place of a hurricane. Governments can educate their citizens on how
to respond in the case of an earthquake.
 Jamaica has developed initiatives such as conducting earthquake drills in public
organization such as schools. There is an annual earthquake drill program organized by
the ODPEM and the education ministry. This initiative prepares students to function
effectively when they are impacted by a major earthquake.
 Haiti- Much of the loss of life caused by the Haiti earthquake of 2010 resulted from the
collapse of poorly built houses. Many of the schools and homes had brittle walls and
unreinforced masonry that simply fell apart when ground shaking occurred.
As the Haitian capital Port-au-Prince is rebuilt, there is a desire to ‘build back better’.
This means constructing new buildings that are built to withstand ground shaking. While

168. Oral Johnson
no building can be 100% earthquake proof, it is possible to build more rigid constructions
that are less likely to collapse. Earthquake-resistant features using reinforces concrete
(concrete with steel rods to give added support), supporting walls and roofs with diagonal
cross beams and buildings to their foundations.
LANDSLIDES
INDIVIDUAL RESPONES TO LANDSLIDES
 If you have not yet constructed, find out the history of the area and determine whether
you really ought to construct there.
 If you go ahead with construction, plant trees and shrubs that bind the soil on slopes and
build retaining walls. In mudflow areas, build channels or deflection walls to direct the
flow around buildings. There may be legal issues if you divert mudflow to your
neighbor’s property.
 Plant or maintain well-rooted vegetation on slope. Plant or maintain well-rooted
vegetation on slopes above and below your property. Don’t remove any trees or
vegetation – unless the trees are diseased and pose a hazard.
 Refrain from doing so much paving that you channel storm run-off to where it will
collect and saturate the soil.
 Maintain good drainage
 Beware of building on steep slopes or cutting into them to level the ground for building.
It must be done properly and, in some places, not at all. Always consult an expert in this
regard.
 Putting too much weight on vulnerable areas can contribute to landslide hazards. So can
vibrations, such as those caused by jackhammers or heavy trucks.
 Beware of changing the natural course of water-ways. This can cause problems, if not to
you, then to others.
NATIONAL/GOVERNMENT RESPONSES TO LANDSLIDES
 The government of Jamaica has been helping the community of Somerset in Portland to
reduce the impact of landslides that have been plaguing the community for years. There

169. Oral Johnson
are plans to the replant about 10 hectares or of 10 (25 acres) of forest. Planting more trees
will prevent runoff and allow for water to infiltrate into soil. In addition check dams are
also being built along the hillside which restrict the movement of soil downslope and
reduce the flow of rainwater. There are also plans to train at least 100 farmers in a
number of a sustainable cultivation practices, which take into consideration and
incorporate the hilly terrain, with the aim of preserving the valuable topsoil, even while
maximizing crop return.
RESPONSES TO VOLCANOES
Hazard mapping
Planning evacuation areas and removing the people most at risk from tectonic hazards is vital in
reducing vulnerability. Hazard mapping allows local areas to limit access to the danger zones
and prevent buildings near to potential hazards from being built. Exclusion zones can also be
created, where no-one is allowed in them before, during or after an event. A hazard map was
created by the Montserrat Government. Almost half of the country to the south is an exclusion
zone. No activities are not permitted in this section of the island.
Warning systems
Some countries have proper warning systems that give residents evacuation order when an
eruption is imminent. Major volcanoes are monitored using special equipment.
REGIONAL RESPONSES
In 1981, following severe floods and hurricane damage, the pan Caribbean Disaster Prevention
and Preparation Project was established. In 1991, this became the Caribbean Disaster Emergency
Response Agency (CDERA). There are currently 16 participating states within the Caribbean.
These are organized into four sub-regional groups
 Jamaica including Belize, the Bahamas, Turks and Caicos Islands
 Antigua and Barbuda along with the British Virgin Islands, Anguilla, St Kitts and
Nevis, Montserrat
 Barbados including Dominica, St Lucia, St Vincent and the Grenadines

170. Oral Johnson
 Trinidad and Tobago with Grenada and Guyana
CDERA’s motto is’ Managing Disasters with preparedness’. The institution was reorganized in
2009 and was given a new name. It is now called CDEMA, the Caribbean Disaster Emergency
Management Agency.
The following are CDEMA’s main functions:
 Make an immediate and coordinated response to any disastrous event in the participating
states. This includes man-made disasters such as oil spills and aircraft accidents as well
as natural hazards.
 Reduce vulnerability of individuals to natural disasters by providing information and
guidance
 Acquiring and channeling comprehensive and reliable information on disasters affecting
the region to interested governmental and non-governmental organizations.
 Provide training for disaster management personnel
 Maintain a dynamic website to provide up-to-date information, for example, weather
forecasts.
A participating state may require assistance in responding to any type of disaster as a long as the
state has determined that control of the situation is beyond its own capability. Hurricane Ivan
(page 149) in 2004 is an example of an event that caused such widespread devastation that those
individual countries (particularly Grenada) simply couldn’t cope with the scale of the disaster.
CASE STUDY- CDEMA Hazard Maps
CDEMA has assisted three Caribbean participating states in creating hazard maps to identify
areas most at risk from floods, landslides and storm surges.
 Grenada- Floods, landslides and coastal erosion.
 St Lucia- floods, landslides, wind/wave and storm surges
 Belize- coastal erosion, wind/wave and storm surges.

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The maps will be used by the countries’ Physical Planning Departments to make informed
planning decisions in the future that will reduce the likelihood of individuals being affected by
natural disasters.

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HUMAN
GEOGRAPHY

173. Oral Johnson
POPULATION
Population facts and Figures
World population passed the 6 billion mark in 1999. Since then growth has continued, reaching
6.7 billion by 2007. Although this appear very rapid, in fact the world growth rate is beginning to
slow down. An approximate way of looking at it is to say that one baby is born somewhere in the
world every seconds and someone dies every two seconds.
Almost 40% of the world’s people live in just two countries: China, the largest, with 1.4 billion,
and India with 1.2 billion. India is currently growing faster than China and is likely to overtake
it. The USA, Russia and Indonesia are the next in population size order. Equally, there are some
very small countries, many of which are island nations, some located in the Caribbean.
Some cities are larger than countries in terms of population. Mexico City and New York are both
close to 19 million, but are outranked by Tokyo at 26 million. The largest Caribbean country is
Dominican Republic with 8 596 000. Jamaica has over 2 million people, Trinidad and Tobago
just over 1 million. Although these are relatively large for the Caribbean, they have fewer people
than most world cities. The British Virgin Islands have only 21 000 people and the Cayman
Islands 41 000.
World population distribution and density
Some definitions
 Population distribution means the way in which people are spread out over an area.
Population distribution is represented by a dot map.
 Population density is the average number of people per unit area. It relates to numbers
of people to the area they occupy and make a living from. Population density is usually
expressed as the number of people per square kilometre. Population density is
represented by a shaded map or choropleth map.
Factors that affect population distribution

174. Oral Johnson
Physical factors that influence population distribution
Climate
The impact of climate is very important. Unfavourable climate is the main reason behind the
world's empty areas. Half the world is almost uninhabitable because of climate difficulties.
Temperature is an important factor to be considered in climate conditions.It is obvious that
wherever there are extremes of temperature, human life is difficult to sustain, and consequently
such areas are sparsely populated. Areas with such climate include the extremely hot and dry
deserts and the polar regions of the world.
Vast areas are too dry such as the Sahara (a hot desert in North Africa), Atacama (desert in
Chile), Kalahari (desert in Southern Africa) and the Gobi (a desert in Western China) for
habitation. The hot deserts cover about 20 % of the world’s land surface, yet support only 0.4%
of the world’s population. Areas such as the Arctic, Antarctic, vast areas of North America and
Siberia are too cold for human habitation. The soil is frozen for most of the year so it prevents
any infrastructural development and agricultural activity.
Conversely areas with temperatures that are not extreme tend to be more suitable for settlements
and will have higher population densities. In addition the rainfall is reliable and evenly
distributed throughout the year and there is lengthy growing season so these areas are densely
populated. For e.g. the tropics and the temperate zones.
Relief/Topography
The main concentrations of human population are confined to the areas marked with flat
topography. Highland areas with its rugged nature restricts the clustering of human population.
When an area is flat or gently sloping or low lying it is easier to construct infrastructure and
communications (road, railways etc). The soils are normally deep and fertile. These areas
encourage high population densities e.g. the plains of Jamaica, plains of North America and
Europe. The Ganges Valley in India, Nile valley in Africa, Hwang Ho Valley and Yangzte

175. Oral Johnson
Valley in China are all areas marked with flat topography that have high population densities.
The most populated areas in Jamaica are found on the major plains.
When the terrain is mountainous it restricts settlement and agricultural development. This further
will result in sparsely populated areas. E.g. Andes, Alps, Himalayas, Rockies, Blue Mountains,
John Crow Mountains, Cockpit country
Disadvantages of Highland/Mountainous areas
 Highland area are characterised by steep slopes which makes it difficult to build houses,
roads and railways.
 Soils on highland/mountainous areas are normally thin and is not suitable for farming
Water supply
Areas with regular water supply will tend to attract a large population. Areas where rivers are
situated normally are densely populated areas. Rivers usually attract people because they provide
a water supply, irrigation, transport and for fishing purposes. Ninety-six percent (96%) of
Egypt’s population lives along the Nile on just 4% of the land available in the whole country.
400 million people live in the Ganges River Basin, making it the most populous river basin in the
world
In addition these rivers have rich soils (alluvium- river deposited silt) and will support faming
there will contribute to the high population densities. Many communities in Jamaica have sprung
up close to water sources, Examples include Constant spring, Golden Spring and Black River.
Vegetation
Vegetation can also influenced distribution. Areas such as the Amazon Rainforest in South
America is dense and creates a difficult environment to exploit. These areas tend to be sparsely
populated. The other rainforests across the tropics are sparsely populated due to this reason. In
addition to the rainforests of the tropics, the coniferous forests of Northern Europe shows similar
conditions. Areas with less dense and thick forests tend to have higher population densities.
Soils

176. Oral Johnson
Similarly, the quality of soils exerts an undeniable influence on the distribution of world
population. Areas which have good quality soils will tend to have a high population densities.
Deep humus filled soils, fertile deltaic and alluvial soils supports dense populations. Most of the
major concentrations of populations in the world are located closed to rivers. The soils close to
rivers are very fertile and hence supports agricultural production. This can support a large
population. Volcanic soils are fertile soils which also support large populations. Some volcanic
regions of the worlds are densely populated due to this reason. The Ganges river in India and the
Nile river in Africa are examples of rivers which supports high population densities
Conversely thin, unproductive or damaged soils cannot produce high yields so fail to support a
large population. For example, The Soils of the Sahel, The leached soils of the rainforest, the
acidic soils of the northern coniferous forest
Resources
Areas with resources often have large populations. Resources attract people to settle and exploit
them so long as they have the technology necessary. Industries usually develop around these
areas with mineral resources. Availability of jobs in these industries will cause this area to
develop rapidly. This will attract other industries and overtime the area will expand rapidly.
Large towns have grown up in inaccessible and extremely inhospitable areas such as deserts,
Polar Regions or in the midst of forests where precious minerals and metals have been found.
Examples are oil reserves in Alaska, Libya and the Middle East. Kalgoorlie, a gold mining town
in the Australian deserts, is a very good example in this regard
All over Northern Canada, where the climate is cold and difficult, towns such a Port Radium and
Grand Rapids have sprung up around mineral deposits or energy sources. In the Caribbean many
settlements have developed around bauxite, oil and other resources.
Human factors that affect population distribution
Availability of services

177. Oral Johnson
Areas with large number of services tend to have high population densities. Examples of services
include health care services, educational institutions, transportation services, entertainment
services. In less developed countries there are sometimes significant differences between the
availability of services in urban and rural areas. Urban areas tend to have more services than
rural areas. Because of this the urban areas are densely populated. Most of the capital cities in the
Caribbean are located in urban areas. The capital cities sometimes have population three times or
more than the next largest city in most countries in the Caribbean.
Availability of Jobs
Wherever jobs are situated there is a tendency for that area to have a high population density.
This means areas where certain economic activities are concentrated tend to have dense
populations. Large populations have developed around inhospitable areas due to availability of
jobs from the development of mineral resources. In less developed countries the urban areas
usually have more jobs than rural areas. This will result in large population densities in the urban
areas.
Government policy
There have also been cases in which governments have influenced population distribution
patterns. The state may directly or indirectly decide to encourage development in a particular
area or region. In modern times, governments have taken a regional view of resource
development and created urban centres to act as economic nodes.
Brasilia, the capital of Brazil is an excellent example. The capital was transferred from Rio de
Janeiro to a site was nearer to the city centre of the country to redistribute the population. It
became the seat of government and headquarters of major Brazilian companies. Population
growth was explosive. Planned for 500,000, the city is now home to 2 million people. Similarly
India’s Capital which was once Kolkata now moved to Delhi has significantly affect the
population distribution there. Delhi is one of the most densely populated areas in India.
Factors that influence population distribution in Jamaica

178. Oral Johnson
Dot map of Jamaica
Choropleth map
Physical Factors
Relief/Topography

179. Oral Johnson
Flat lands are ideal for settlements, construction of infrastructure and for farming. Most
settlements in Jamaica, especially the towns are on the low lying plains on the southern section
of the island. The plains in Jamaica are: Ligunea (Kingston and St Andrew), Pedro plain (St
Elizabeth), Vere plain (Clarendon), Georges plain (Westmoreland), Dorothy plain (St Catherine).
With the exception of Mandeville all parish capitals are on low lying plains or along the narrow
coastal strip around the island. The towns have the largest populations. Kingston, the largest
settlement in Jamaica is on the Ligunea plain at the foot of the Blue Mountains.
Like many other Caribbean territories Jamaica is hilly, with some areas being very high over
(2000m). Settlements was difficult for early settlers as the hills were very difficult to traverse.
Even with today heavy equipment, like excavators and power cranes, some areas are still
difficult to cut roads through. The Blue Mountains, Cockpit Country and John Crown in the east
of the island are not only high but also steep. Settlement in these areas will always be difficult
and so they will have a sparse population. The dolphin head at the western end of the island also
have a sparse population.
Water supply- Water is life- This is a frequently used slogan of the national water commission
of Jamaica, because water is indeed one of the basic essentials for survival for both plants and
animals. Before technology brought us pumping stations and piped water people settled near
river and springs where they had easy access to water.
Many settlements in Jamaica sprang up beside rivers and springs and took the name of the local
water source for example constant spring and Golden Spring in the parish of St Andrew. Others
include Black River, Rock Spring, Ulster Spring, Mason River, Rock River, White river and Mill
Bank along the Rio Grande River. These are some larger settlements but many smaller
settlements are also named after water sources.
Drainage: In theory areas that have good drainage tend to have a dense population whilst areas
that have very poor drainage will deter settlement and have a sparse population. In Jamaica there
are areas where the drainage is poor and these areas have low population densities. They include
the Great morass of Westmoreland and Hanover, St Thomas and St Elizabeth (along the black
river)

180. Oral Johnson
It is difficult or almost impossible to construct buildings and roads on swampy areas. It is
impossible to cultivate swamp lands. The stagnant water found in these area are ideal breeding
ground sites for mosquitoes and some of them are vectors for diseases.
Natural resources (minerals): Some areas in Jamaica are rich in Bauxite ore. The town of
Mandeville in the hills of Manchester developed as a result of local bauxite mining. Today,
though, bauxite production is significantly reduced, and many of the hotels and apartments in the
town that once housed expatriates are now offices. In other areas where aggregates like
limestone and gypsum are mined, small communities sprang up around the activity- for example
Bull Bay in St Thomas.
Access to the coast: Most Jamaican towns are situated along the coast, especially in the north.
The earliest settlers- the Tainos (formerly called Arawak’s_ were hunter- gatherers and
fishermen and they mostly settled along the coast. Discovery bad and Runaway Bay are old taino
settlements that have grown into large modern settlements. The Europeans also settled along the
coast and developed trading posts. The sea is also a source of revenue for many communities in
Jamaica. There are many fishing communities along the coast of the island and these persons are
directly dependent on the sea as a source of income. Examples include Port Royal on the
palisadoes strip, Old Harbour bay in St Catherine and Alligator Pond in Manchester.
The highest concentration of population are found in coastal areas with about two-thirds of the
world’s population living within 500 km of the sea.
Soils
Fertile soils have the effect of attracting people. There are different soil types in Jamaica but a
very common one due to the numerous rivers is alluvium. A good example is in the Bog Walk
and Linstead Area in St Catherine. This area have fertile alluvium soils which attracted people. It
attracted farming activities such as the cultivation of citrus crops and Sugar Cane. The
development of these activities attracted other types of economic activities to the area. Over time
the area continued to grow and expand.
Vegetation

181. Oral Johnson
There are areas in Jamaica that are heavily forested and as a result difficult to exploit and
expensive to clear e.g. the Blue Mountains and the Cockpit Country. These areas are sparsely
populated. Areas that have less dense vegetation for e.g. on the plains are densely populated.
Human factors affecting population distribution
Economic Factors
This relates to the availability of jobs. The urban areas provide more job opportunities than rural
areas. This encourage large rural to urban migration. This is most noticeable in Kingston as
many persons from rural area from different parishes go to Kingston to seek jobs. This is also the
case in Montego Bay which is the second largest city in the country. These areas are the densest
in the country.
The recent development of tourism in the north eastern section of the country have resulted in the
creation of jobs. This has resulted in a large influx of migrants from rural areas to this section of
the country due the availability of jobs in the industry.
Social Factors
This relates to the availability of services. Similarly in urban areas there are wider range of
services compare to rural areas. Examples include health care services, educational institutions,
transportation services, entertainment services. Better utilities and infrastructure such as water
supply, electricity are available in the city.
The two most recognized tertiary institutions are in Kingston, The University of the West Indies
and University Technology of Jamaica. After leaving high school many students from rural areas
migrate to Kingston in searching for higher education. Even after leaving school persons stay in
Kingston as the chance of getting a job is higher. This is another reason why Kingston is so
densely populated. There is a similar effect in Montego Bay as there is another University of the
West Indies campus located there alongside the various services that can be found in Kingston.
Because of the wide range of services available in urban areas they will continue to attract
people.
Government policies

182. Oral Johnson
Government policies also affects population distribution in Jamaica. In 1872 Kingston became
the capital of Jamaica after Spanish town was the capital for 217 years. This created a shift as the
services and population also shift with it as well.
Modern examples include the development of Portmore. Portmore was developed solely to
control the overpopulation problems that was in Kingston. It was particularly created to relieve
the housing pressures. Because of this, the area now is one of the most populated areas in the
country. The area is well developed and there are a wide range of services available there.
Persons who lives in Portmore commute to Kingston daily where there jobs are.
Historical
There are many isolated communities across Jamaica. These settlements are influenced by
historical events. A good example is Accompong Town which is a historical Maroon Village
located in the hills of St Elizabeth. Accompong was founded in 1739 and their descendants
fought a protracted war with the British. A treaty was signed which saw the maroons given 1500
acres of land in the Cockpits. The community was established back then and still exists after 279
years.

183. Oral Johnson
Population trends
Birth rate, death rate and natural change
The birth rate (BR) of a country is defined as the number of live births per 1000 of the
population in a given year. The reason ‘per 1000’ is part of the definition is so that countries of
different sizes can be compared. Otherwise, how could China with its 1.4 billion population be
sensibly compared with Jamaica, a country with a population of 2 672 000? Often we record
statistics as percentages. If BR was measured in this way the numbers would be small and more
difficult to grasp. Using ‘per 1000’ is much more manageable.
Birth rates vary between 5/1000 per year and 50/1000 per year. These extremes are both very
unusual. Most countries have a BR between 10 and 30 per 1000 per year. Jamaica’s BR was
20.4/1000 in 2007; Trinidad and Tobago’s was 13.1 per 1000 in the same year.
The death rate (DR) of a country is the number of people dying per 1000 people per year in that
country. Jamaica’s death rate was 6.6 per 1000 in 2007 while Trinidad and Tobago was 10.8 per
1000. Typically death rate lies between 5 and 20 per 1000 per year. Periods of national crisis,
such as war or epidemic disease, would increase the DR above this level. Once we have these
two statistics we can start to work out population change- that is population growth of decline.
This is called natural change and is calculated by simple subtraction. It is the difference between
BR and DR.
Calculating natural change
Natural increase (NI) means a country has a growing population. Birth rate is higher than death
rate, so the calculation is:
NI= BR-DR
Natural change (NC) or rate of natural increase is always expressed as a percentage, so the
answer must be divided by ten.
Example the UK
Birth rate= 10.7 per 1000 per year
Death rate = 10.1 per 1000 per year

184. Oral Johnson
NI as a percent ( or rate of natural increase)= BR-DR/10
= 10.7- 10.1/10
= 0.6/ 10 = 0.06 % per year
Example: Mauritius ( a developing country)
BR= 15.3 per 1000 per year
DR= 6.9 per 1000 per year
NI= 15.3 – 6.9/10
NI= 8.4/10
NI= 0.84%
Until recently all countries have been in a situation of natural increase unless war, famine or
disease has reversed this for a limited time. Today, however, some countries, mostly in Easter
Europe, are in a state of natural decrease (ND). To calculate ND, BR is subtracted from DR.
Example: Czech Republic (a poorer developed country, which joined the European Union in
2005).
BR= 9.0 / 1000 per year
DR= 10.6 / 1000 per year
ND= DR-BR/10
ND= 10.6- 9.0/10
ND= 1.6/10 = 0.16% year decrease
Birth rate, death rate, natural increase and natural decrease give us information on the level of
development of a country. Today, in all countries, rich or poor, DR tends to be low. People often
assume that death rates in developing countries must be high because people are poor and life
expectancy may not be very long. This is not true. Two factors affect the level of DR: improved
health care and the youthful age structure of these countries. Death rates in developed countries
are often higher than those found in developing countries because they have a larger number of

185. Oral Johnson
elderly people. Birth rate is a better indicator of development. In all developed countries family
size is relatively small, but developing countries have good economic reasons for favouring
larger families.
More useful definitions
Infant and child mortality rates and life expectancy are also useful indicators of development. In
countries with developing economy the first two tend to be higher and the last tends to be lower.
Countries achieve a longer life expectancy as they develop economically, but, sadly, many
African countries are now seeing their life expectancy figures being reduced to due to the impact
of AIDS. This has happened in South Africa, Zimbabwe and Botswana.
The infant mortality rate is the number of deaths in the age group 0-12 months per 1000 live
births per year. The child mortality rate relates to children up to their fifth birthday. Life
expectancy is the number of years people in a particular society are expected to live. The highest
life expectancy in the world is for Japan: over 80 years old for both males and females. Life
expectancy figures can be split by gender and it is usually higher for females for males. A small
number of European countries now have a life expectancy of 80+ for females, but not yet for
males; only Japan has achieved that so far.
The demographic transition model
The demographic transition model shows the changes or patterns of birth and death rate over
time. Migration is not included. It is divided into five stages during which there is a change from
a situation of high birth rate and death rate to low birth and death rates. Originally the model was
designed to explain patterns in the developed countries but it can also apply quite well to today’s
developing regions of the world.

186. Oral Johnson
Stage 1
In stage 1 both the birth rate and death rate are both high and fluctuating. This stage is called the
high ‘fluctuating stage’. Birth rates are high owing to high infant mortality, lack of birth control
and need for children to work on the land. Death rates are high owing to famines, war and
disease. It refers to a simpler society than we find today, with little medicine, a low life
expectancy and no mean of birth control. The only places where this stage still applies might be
among indigenous people in remote rainforests in Amazonia or Indonesia, but even they now
have some influence from the outside world.
Stage 2
In stage 2 the birth remains the same but the death rate fall rapidly. Death rates fall as medicines
are introduced, health care improves, and there are better diets and improved living conditions
(safe water and sanitation). This results in a natural increase and the population starts to increase.
The key characteristic of stage 2 is a decreasing death rate. The gap between the BR and the DR

187. Oral Johnson
on the graph represents population growth. The farther apart these lines are, the greater the
growth.
Stage 3
In stage 3 the death rate continues to fall, but at a more gradual rate. The key change is that birth
rate now falls, and often quite rapidly. This is due to several reasons. Women are now focusing
on self-development and pursuing careers rather than having multiple children. This is also due
to the availability of birth control, but people must have an economic reason for desiring birth
control. As a country develops children become economic costs rather than economic assets.
When children can work and earn they bring money into the family, but when they have to go to
school (which may cost the family money) they can contribute less. It is therefore become cost-
effective to have fewer children.
Stage 4
In stage 4 both the birth rate and death rate are low. This is called the low fluctuating stage. The
lines on the graph are close to each other and birth rate is still higher than the death rate, so there
is still population growth but it is slow. A country in this stage is developed and there are several
reasons for having a small family.
Stage 5
The original DTM did not include this stage. It was added later to try to explain recent
demographic changes in some developed countries where, for the first time in human history,
birth rate is less than DR. More people are dying than are born each year. Many eastern
European countries and some western European states are now in this situation. Germany, Japan,
Greece, Spain and Italy are some good examples.
The position of the Caribbean in the DTM
Most Caribbean countries can be placed stage 3 of the demographic transition model. Because
they are developing economically their DR has been low for many years and their birth rate is
also declining. Within a few decades the Caribbean region should enter stage 4
Reasons for higher birth rates in LEDCS

188. Oral Johnson
Hardly any part of the world does not have access to birth control today, only the most remote
regions like Amazonia. In some cultures the position of women and traditional life make birth
control less acceptable such as Afghanistan, which still has one of the world’s highest birth rates
of 38.84/1000 per year. Lack of education may mean people have difficulty accepting new ideas.
Religion
Religion had also had an impact on the acceptance of birth control. The Roman Catholic faith
does not agree with birth control, so Catholic countries have traditionally had larger families. In
some Muslim societies the position of women is low and this encourages a high birth rate,
though there is no basis for this in the Koran. Girls tend to marry young so there is a longer
period in which to have children.
Children needed to work on the land
In a peasant farming society children are needed to work on the land; they can produce more
food than they eat. Even in the cities children are able to earn some money to supplement the
family’s income.
Cultural traditions
Some cultures prefer sons to daughters. Several children may be born to ensure at least two sons.
In India, for example a bride must bring a dowry (a payment at marriage) to her new husband’s
family. It is therefore expensive to have daughters. Sons also carry on the family name; if you
produce only daughters, the name will die out. This is particularly important in China. In other
cultures men are polygamous (have more than one wife) and having several wives was a sign of
wealth and status for a man.
Children seen as pension plan
LEDCs have little state care for the elderly. Parents expect their children to look after them in
their old age. This is not only a reason for having a larger family, but also for having sons, as a
man is in charge for his household, not his wife. A man is more able to care for elderly parents
financially. There are few pensions or services for the elderly in LEDCs.

189. Oral Johnson
Reasons for low birth rates in MEDCs
Emancipation of women/ women are more career oriented
Two factors are important in reducing the birth rate as a country develops. In an MEDC,
education is compulsory for boys and girls until the age of at least 16, or higher, and many
continue their education at university. Marriage is therefore later. Women have the chance to
develop a career. They therefore choose to have children later or even not to have any at ll. Most
women have to work outside the home. It takes two incomes to buy a house and look after a
family. A working mother with limited time is likely to choose a smaller family.
Cost of raising a child
Children are also expensive. They cannot go out and earn money for the family but it costs a
good deal to bring them up in a country with high standard of living. People prefer to have one,
two or three children and give each as much as they can afford, rather than dividing the family
resources between more children.

190. Oral Johnson
Population growth
Factors affect population growth in Jamaica and China
Some of the factors that affect population growth are: fertility rate, birth rate, natural increase,
migration, fertility rate, and life expectancy and government policies.
Population growth in Jamaica
Factors that affect population growth in Jamaica
The population of Jamaica increased rapidly in the 1900’s but in recent times, the rate of growth
has decreased. Though the population is still growing, it is not growing as quickly as it was in
past decades. The line graph below shows that population growth in Jamaica has generally been
on the decline for some time. In the early 1980’s the population growth rate was almost two
percent but by 2011, the rate had dropped to about a quarter of one percent.
Fertility rate
The average number of children women are having now is significantly smaller than what is used
to be in the past. In the 1900s the population increased rapidly. Having more than 5 children was
a norm in the 1900s. One of the issue was a lack of birth control. Couples had large families
because they needed children to work on farms as farming was the major economic activity. In
addition some couples have multiple children so their kids can take care of them when they reach
retirement age. Children were seen as an economic resource rather than a burden. The average
number of children is a family has halved in thirty years. There are many reason for this. Birth
control is now readily available. More women are working, giving greater freedom to plan
independently. In Jamaica, two thirds of women have jobs, one of the highest ratios in the world.
More women than men enter higher education. In 1960 Jamaica’s fertility rate was 5.42 and it
was 2.02 in 2015. The decrease in fertility rate has a negative effect on population growth.

191. Oral Johnson
Birth rate
The birth rate is similar to the fertility rate and has also decreased due to the same reasons. The
birth rate in 1960s was 41 per 1000 and in 2015 it was 17 per 1000. Women are now more
career oriented thus delaying child bearing. Also birth control is more readily available. The
decreased in birth rate also has a negative effect on population growth.
Death rate
There is not a significant change in the death rate as the birth and fertility rates. The introduction
of modern and western medicine have significantly improved medical care. The death rate in
1960 was 9 per 1000 of the population while the death rate in 2015 was 7 per 1000. The death
rate has remained the about the same.
Natural increase
The rate of natural increase is lower, because of the falling birth rate. In 1960 the natural increase
was 32 per 1000 and in 2015 it was 10 per 1000. As women begin to pursue their career and
have fewer children and smaller family, there is a significant reduction in the rate of natural
increase.
Life expectancy
Life expectancy has increased and infant mortality has decreased as a result of improvements in
living conditions and medical care. This will tend to have a positive effect on the rate of
population growth. Life expectancy in the early 1970s was 69. Now the life expectancy is
approximately 77 years. Infant mortality rate has been cut by two-thirds
Migration
There is a significant outflow of migrants to the USA, Canada, Britain and other Caribbean
territories. There is a much smaller number of people moving into Jamaica from other countries.
Since emigration is greater than immigration, this will have a negative effect on population
growth

192. Oral Johnson
Factors affecting population growth in China
Fertility rate: There has been a significant reduction in the fertility rate in China. In 1960 it was
5.7. Previous Chinese governments encouraged people to have a lot of children. This was done to
increase the country’s work force and military power. However, in the 1970s the government
realized that the rates of population growth would soon become unsustainable and will soon face
famine conditions. In the late 1970s, the Chinese government introduced a number of measures
to reduce the country’s birth rate and slow the population growth rate. The most important of the
new measures was a one child policy which was implemented in 1979. The fertility rate in 2015
was 1.6. See government policy below
Birth rate
With the lower fertility rate, the birth rate is also declining. The birth rate in 1960 was 44 per
1000 and the birth rate in 2015 was 12 per thousand. The decline in birth rate is due to the
implementation of the one child policy.
Life expectancy
Life expectancy has increased by 43 in 1960 to 76 in 2015. Arguably, improvement in the
provision of public health services particularly in infant and mental health have been the biggest
factors in raising life expectancy. The improvements in medical care was not drastic but a slow
process. Its effect on population growth is positive as people are now living longer. Ten percent
of China’s population is over 65 compared to 4% in 1960.
Death rate
In 1960 the death rate in China was 25 per 1000, the death rate has fallen to 7 per 1000 in 2015.
There has been significant improvement in China’s health care. There is better control and
prevention of infectious diseases which also lowered the infant mortality rate which ultimately
increased life expectancy. Infant mortality rate fell from 84 per 1000 live births in 1960 to 8.5
per 1000 live births in 2015. The falling death rate has a positive effect on population growth.

193. Oral Johnson
Natural increase
There is a fall in the natural increase as there is a decline in birth rate. The natural increase fell
from 20 per 1000 in 1960 to 6 per 1000 in 2015. The decline comes as a result of one child
policy. The reduction in natural increase has a negative effect on population growth.
Migration
There is an outflow of Chinese to different destinations across the world. There is a much
smaller number of people moving into China from other countries. Since emigration is greater
than immigration this would have a negative effect on population growth.
Government policy:
The policy China decided to introduce was extremely strict and probably not possible in a non-
communist country. The government stated that from 1979 all couples were only allowed to have
one child. Each couple:
 Must not marry until well into their twenties.
 Must only have one successful pregnancy.
 Must be sterilized after the first child or abort any other further pregnancies
If you applied by these rules you were entitled to free education, healthcare, housing and given a
job. If you did not follow the rules, then benefits would be removed and females who were
found to be pregnant were given forced abortions and even sterilized.
To enforce the policy
 The government relied on community enforcement. Often elderly residents who were
trusted within the community were asked to inform, elderly female informants were
nicknamed 'granny police'.
There were a number of exceptions to the rules,
 if your first child had a physical or mental disability you could have a second,
 Families in rural areas (farming areas) were often allowed a second, ethnic minorities
were allowed a second and often couples who bribed officials could have a second.
SUCCESS The policy has been relatively successful, birth rates have fallen from a peak of 44 in
the 1950's down to just 12. Because of its success there have been further relaxations including

194. Oral Johnson
The policy was controversial for several reasons:
 Later abortions were carried out
 Women were placed under tremendous pressure.
 Local officials had power over people’s private lives
 As sons were preferred, many girls were abandoned or were left at orphanages. Some
were later adopted by Western families.
 Chinese children have a reputation for being indulged because they are ‘only’ (single)
children
The main result of the police has been a rapid reduction in China’s population growth rate. The
likely famine has been avoided. The country is still growing, but much more slowly. It is now
possible to pay to be allowed to have a second child, unless you are a government employee
(government employees are expected to set an example to others, by not having a second child).

195. Oral Johnson
Population Structure
Age structure shows the proportions of each age group within a country’s population. This
varies between developing countries and developed countries and within a country as it develops
over time. Gender structure- the balance between males and females- is also important. Small
differences here can tell us a lot about a country.
Population pyramids
A population pyramid is a bar graph diagram used to show the age and gender structure of the
population of a country, city or other area. The horizontal axis is divided into either numbers of
percentages. The central vertical axis is divided into age categories, either every ten years, every
five years, or ever one. The lower part of the pyramid is the base and shows the younger section
of the population. The upper part is concerned with the elderly group. Pyramids give us a
remarkable amount of information about a population: birth and death rates, life expectancy, and
the level of economic development (or stage of the DTM).

196. Oral Johnson
Interpreting population pyramids
- A broad/wide base indicates a high birth rate. This is typical of developing countries and
they tend to have a young or youthful population. Sometimes majority of their
population is below age 15. There are several reasons for the high birth rates
- A narrow base indicates a low birth rate. This is typical of developed countries. Women
are career oriented, availability of birth controls and the cost of raising children are some
factors that contributes to this.
- A broad apex indicates high life expectancy (top heavy). The bars at the top are
wide/broad. This is typical of developed countries. These countries often times have an
aging population where a good percentage of the population is over 65. Persons are living
longer as these countries have advance medical care.
- A narrow apex indicates low life expectancy. This is typical of developing countries
- If there is a decrease in the width with each successive bar (sides narrow in quickly), this
shows a high death rate.
- Sometimes the bars in the economically active age groups are significantly wider. This
reflects migration as sometimes there are high levels of in migration in a country.
- Sometimes a bar can be missing or be significantly smaller on the male side in a country.
This show the effects of wars.
Population structure of MDCS and LDCS
The population structure in more developed countries tend to show a narrow base reflecting
lower birth rates and a relatively small proportion of its population under age 15. They typically
have a higher percentage over 65 years. The base is narrow which indicates a low birth rate, the
fertility rate is sometimes below replacement .The apex of the pyramid tends to be broader than
those of less developed countries because life expectancy is high. Medical care is available from
cradle to the grave ensures low infant mortality rates and long lives. Japan has 27.87% of their
population over 65 years and 12.84% under 15 years. This means Japan has twice as much old
people than young people.
Generally the population structure of LDCs is marked by a higher proportion of young persons.
LDCS usually have a larger percentage of their population below age 15. These pyramids have a
broad (wide bases) because of high birth rate. The apex of the pyramid is small/narrow which

197. Oral Johnson
indicates a low life expectancy. Niger has 52% of their population below age 15 and only 2.64%
over 65 years old.
The effects on a country of having a young population
The whole of Africa ( except south Africa), most of South America, India and its neighbors,
Mongolia and North and South Korea have over 40% of their people under age 15 years. This
places very specific demands on the governments of these countries.
Whilst there are so many children in the population, more of the services they require will have
to be provided: schools, baby clinics and youth centers. Funds for this come from the
government, from taxes paid by those of working age. A lot of pressure is placed on the
economically active age group as they have to support the needs of the young population.
Governments often increase taxes on the working age group in order to facilitate the needs of the
young population.
On the contrary, countries with the highest percentages of children are generally the ones that do
not have the funds and so cannot supply these for their population
The effects of having a an elderly population
Life expectancy is higher in developed countries than in developing countries, so it is the
developed countries that have the difficulties associated withhold age. In richer countries people
expect to be able to retire from work and have a pension (income) on which to live. Funds for
this come from the government, from taxes paid by those of working age. The demand for
health care increases because more illness occurs in old age. As people live longer, even greater
pressure is placed on the system. The government has to find more funds, again from taxation of
present workers.
Elderly people need certain services in particular: nursing homes, day care centers and people to
assist the elderly in their own homes. These special needs also put financial pressure on the
country.
Population pyramids and the DTM

198. Oral Johnson

199. Oral Johnson
URBANIZATION
Urbanization is the process whereby an increasing percentage of the population in a country lives
in urban settlements. Urban growth is the actual increase in size and total population of urban
areas.
According to the United Nations:
Around 5 billion people are expected to live in urban areas by 2030. This will be about 60% of a
world population 0f 8.1 billion. At present about 75% of the population of developed countries
live in urban areas. This figure should rise to 83% by 2030. This compares with 40% of the
population of developing countries living in urban areas today. This will increase to 56% by
2030.
Causes of rising urban populations
Rapid urban growth is the result of three factors:
 Natural increase- the excess of births over deaths in most urban areas, particularly in
developing countries.
 Rural-urban migration- The perceived higher quality of life in urban areas as opposed to
rural areas has resulted in high rate of migration from the country side to towns and
cities. This has been at a very high rate in developing countries since the 1950s.
 Reclassification – rural villages that have expanded rapidly to become towns are
reclassified as urban areas. In such cases long-standing residents who will have
previously seen classed as rural dwellers because their settlements have expanded in size.
The two most important factor in urban growth are natural increase and in migration.
Push and pull factors
A variety of push factors in the country side has encouraged out-migration.

200. Oral Johnson
 There are not enough job opportunities available in rural areas. This results in
unemployment.
 The poor wages and conditions of rural employment
 There are not enough services such as schools, health facilities and recreational activities
in rural areas. Most tertiary based institutions are usually located in the urban areas of a
country for e.g. Jamaica. The social conditions in rural areas are poor.
 In some rural areas, the conditions of infrastructure ( electricity, water, sanitation and
roads are often lacking
 Agriculture is declining in rural areas in many countries and there is an expansion of the
service and manufacturing industry in the urban areas. The idea of farming is not
generally attractive to young people so there is a tendency to move to urban areas.
A variety of pull factors in the urban areas has encouraged in in-migration. People are attracted
to urban areas because they feel that life in town and cities will provide at least some of the
following:
 A much wider range of jobs and a greater likelihood of employment. The manufacturing
and service sector jobs are often located in urban areas. Call centers are expanding in the
Caribbean now and majority of them are located in urban areas where there is a large
educated labor force. After finishing university in Jamaica, most of the graduates stay in
Kingston as there is a higher chance of getting a job there. Therefore many people move
to towns and cities in search of employment.
 Urban areas also have better educational opportunities. Most secondary and tertiary level
educational facilities are to be found in towns and cities. In Jamaica some of the top
tertiary institutions are located in Kingston for e.g. UWI, UTECH, MICO and EDNA.
After students graduate secondary school they move to Kingston to attend these schools.
 Urban areas generally have better healthcare facilities than rural areas. Indeed, some
rural areas have no healthcare facilities at all.
 Urban areas provide more opportunities for entertainment than rural areas. In urban areas
one may find nightclubs, fancy restaurants, sports facilities, shopping malls and many

201. Oral Johnson
other opportunities for entertainment and recreation. These are particularly attractive for
young people.
 A wider range of consumer services such as food markets and different kinds of shops.
 Proper infrastructure- roads, water, electricity etc
The scale of rural-urban migration in developing countries is not surprising given the great
concentrations of wealth and economic activity in the cities compared with the countryside. For
example Caracas accounts for 75% of all the manufacturing industry in Venezuela. Because of
urbanization cities across the world are rapidly increasing. Some cities for e.g. Barcelona and
Milan have more than one million people and are termed million cities. Some cities which have
populations of 10 million or more. These are termed megacities. Tokyo, Mexico city, Sao Paulo,
New York, Mumbai, Los Angeles and Kolkata are all mega cities. Eight (8) percent of the
world’s population live in megacities.
Urban primacy
In developing countries and some developed counties socio- economic, cultural and historical
factors usually result in the dominance of one or few urban areas. Most of the economic
activities, services and government administration are located there. Urban primacy exists
when one or a few cities dominate the settlement system in a country. A primate city is one
that is at least twice the size of the next largest city. London which is six times larger than the
next largest city in England; and Paris which is ten times larger than the next largest city in
France. Kingston is at least 3 times larger than Portmore. In most Caribbean countries over 30%
of the population live in or very close to the largest city. The main concern about urban primacy
in the Caribbean is the heavy concentration of investment in capital cities which has let little
investment for elsewhere.
Benefits of Urbanization
Some of the benefits of urbanization include:
 Convenience: A wide range of goods and services are conveniently located in the same
area.

202. Oral Johnson
 Many businesses prefer to be located in urban areas in order to have access to potential
customers, employees and other businesses which supply them with inputs.
 Efficiency: Services such as piped water, electricity, telecommunications and even
garbage collection can be provided more efficiently in urban areas
 Majority of the urban residents are in the economically active age group. This results in a
large labour supply for industries. Call centers are expanding in the Caribbean regions
and they are primarily located in urban areas due to this large labour force.
 Large urban areas are more likely to attract new businesses. This is because cities have
better facilities and a more highly skilled workforce than smaller settlement.
Problems of urbanization
Shortage of land for building
In many cities, there is a shortage of land for building. As a result, cities often spread out onto
the surrounding areas. This is known as “urban sprawl”. A good example of urban sprawl has
occurred in Jamaica as the capital, Kingston, has spread outward into the surrounding areas such
as St. Andrew and Portmore. Urban sprawl is the uncontrolled spread of urban development
into surrounding lands (farmlands, green spaces)
Traffic congestion
Since many people travel to cities for work or school, there may be very heavy traffic on the
roads leading into these areas on mornings. Traffic is also quite heavy on afternoons as people
make their way home from work or school. There may be traffic congestion during these periods
as the road networks are often incapable of handling such a heavy flow of traffic.
A lot of persons commute from surrounding areas e.g. Portmore and Spanish town into Kingston.
In addition some commuters live as far away as May Pen and Mandeville. The road network in
Kingston cannot cope with the large volume of traffic and this results in congestion. It is visible
in the early mornings and late evenings.
High levels of unemployment

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Due to the rapidly growing population, there are not enough jobs available for everyone.
Additionally, some migrants are unskilled and therefore can’t find jobs. The high unemployment
rate in Kingston has forced many residents to create their own jobs resulting in a growth in the
informal sector. E.g. persons selling fruits on side walks
Crime
The migration of unskilled and unemployed persons may contribute to high levels of crime. In
some parts of Kingston for example at stop lights, it is not uncommon to find young boys doing
odd jobs. They are forced to do these jobs as a result of their poverty stricken situations when
they should be in school and many times they end up joining gangs and perform criminal
activities.
Pollution
There are different sources of pollution emanating from urban areas. The exhausts from motor
vehicles, the dusts from construction sites and the fumes coming from factories in urban areas
result in air pollution. The noise coming from night time entertainment, continuous flow from
traffic and from construction work creates noise pollution.
There are also cases of water pollution. In some communities in Kingston Jamaica there is
improper disposal of domestic waste. Kingston is drained by some 21 gullies. Residents dump
the garbage in the gully when it is dry. After some heavy rains all the garbage is washed into the
Kingston Harbour where it pollutes it. The sewage produced by Kingston is dumped in the
Kingston Harbour. This sewage is normally treated before it is dumped. However, due to the fact
that the sewage treatment plants are unable to treat all the sewage produced by the increasing
number of persons who live in Kingston, the untreated sewage is being dumped in the Harbour
resulting in pollution of the water
Poor housing conditions
Due to the fact that some persons who migrate to Kingston are unskilled and are unemployed,
they are forced to land (vacant lots) illegally. Very often houses made by squatters are built with
inferior materials (board, zinc) and lack basic amenities such as running water and electricity.

204. Oral Johnson
These areas may eventually deteriorate in to slums, which are both unsightly and unhealthy to
live in.
Controlling urbanization
Development of new towns
One way of controlling urbanization is to build new towns. Portmore in St Catherine Jamaica
was developed primarily to solve the housing shortage in Kingston. It is now one of the largest
residential developments in the Caribbean and has been awarded municipal status by the
government. Freeport in Bahamas is also an example of a new town.
Decentralization of services
One of the main causes of urbanization are the lack of services (education, entertainment, health)
in rural areas. Encouraging development away from cities in rural areas can help combat the
growth of large cities. Some countries in the Caribbean have made attempts to decentralize
services.
In Cuba, the government controls almost everything. In 1963 the government adopted the
Havana strategy. The idea was to stop Havana from growing so the rest of the country could
catch up. Great efforts were made to improve education and health in particular in rural areas.
This would lessen the impact of additional push factors in rural area. This strategy has
particularly been successful.
Trinidad and Barbados both implemented physical development plans in the past to reduce
regional imbalance and dominance of one urban area. However for both countries limited
progress has been made as people and businesses do not always want to do what the government
thinks best.
Providing jobs in rural areas
Providing jobs in rural areas will also prevent urbanization from occurring. The development of
tourism in many rural areas of the Caribbean has pulled away some of the urban population.
Montego Bay and Ocho Rios are now large urban centres. In Puerto Rico industrial estates and
resort areas have develop in rural areas to provide more jobs to the rural population.

205. Oral Johnson
Heritage tourism and ecotourism are being promoted as means of conserving rural environments
while providing jobs for people. Eight Caribbean territories have adopted the UNESCO Youth
PATH (Poverty Alleviation Through Heritage Tourism) program as a means of providing a
livelihood for young people in rural areas while encouraging them to stay and develop these
areas.
Diversifying agriculture
Plantation agriculture and traditional crops have failed in the region in the past two decades.
While some territories have shifted the economic focus from agriculture, others have diversified
the crops grown in order to maintain the rural economy. Non-traditional exports such as pepper,
citrus fruits spices and vegetables have are now being grown for export.
Land use zoning laws
In a number of large cities a green belt policy has been adopted to protect farmed or wooded
areas at the edge of cities from development. Green belts:
 Limit urban sprawl
 Provide recreational opportunities for the urban population
 Prevent loss of farmland
 Protect wildlife

206. Oral Johnson
MIGRATION
Caribbean international migration: patterns and consequences
Caribbean people have history of going abroad to find work or for educational opportunities. In
recent decades, emigration has been a major process in the Caribbean. However, there are also
examples of migration within the region. The Cayman Islands and the Bahamas have increased
their populations considerably through this process. It is not uncommon for individuals to
emigrate to the USA or other countries, leaving their spouse and dependent children behind.
Women have played an increasing role in emigration from the Caribbean. This has been called
the ‘feminization of migration’.
Emigration has been caused by:
 economic hardship
 limitations to professional advancement
 outbreak of civil unrest and violence
 natural disasters
 alienation within island society
 recruitment efforts by US agencies
Changes to immigration laws in both the USA and Canada in the 1960s made migration from the
Caribbean to these countries easier. However, at about the same time it became more difficult to
migrate to Britain. The USA is the major destination for Caribbean emigrants. There are well-
developed networks between Caribbean communities and immigrant areas in the USA and
Canada in particular.
Consequences of out migration in the Caribbean (Jamaica)
 Because the outflow of migrants from Jamaica is much greater than the inflow of
migrants to the country population growth is reduced. In 2003, Jamaica’s natural
population increase was 34, 100. There was net outward migration of 17,700. So
population growth was only 16400, less than one quarter of the natural increase.

207. Oral Johnson
 Most emigrants are young people who would probably have children in Jamaica if they
remained there. Therefore, migration helps reduces birth rate.
 Brain Drain- Migration flows are selective. Young and ambitious people are more likely
to migrate. Most migrants are young, talented, ambitious, skilled or educated. These
people may/would have made great contributions to their home country if they had
remained there. There are several countries, for e.g. England, where there is a demand for
professionals such as teachers and nurses. Jamaica, like many other countries loses many
of its skilled, trained and educated people through migration.
 Caribbean countries such as Jamaica obtain revenue from taxes from persons in the
economically active age group. The tax base is reduced when persons from the working
age group migrates and a country’s economy is significantly affected. This is the case for
most Caribbean countries as it’s the working class people who are migrating.
 One of the positive effects of emigration is that there is a reduced pressure on social
services and employment prospects. When professionals migrate positions are left vacant
and these can be filled by unemployed persons.
 Remittances – Most migrants send money home to their families. These payments are
called remittances. In some years, they are enough to pay for one-third of Jamaica’s
imports. Remittances bring in as much as tourism or export earnings from bauxite and
alumina. In 2000, remittances amounted to about US 1.4 billion. This a total of 15% of
Jamaica’s GDP. Migrants also send back gifts to family members. There may be a
‘barrel’ at Christmas, or a specific purchase when the need arises.
 Tourism – Overseas Jamaicans who return to visit friends and relatives are officially
counted as tourists, and support an important part of the tourism industry. In Jamaica,
they made up 8% of tourist arrivals in 2009. They may stay in hotels or with their
relatives. They spend money on rental cars, restaurant meals or shopping. In Trinidad and
Tobago, returning nationals make up 55% of tourist arrivals.
 Some emigrants eventually return to Jamaica. Some return after retiring or after acquiring
some qualifications or skill. Some may have substantial savings which they may use to
start a business. This creates employment opportunities for persons in the country.
 Some migrants are forced to return to Jamaica. Some are deported for being in these
countries illegally or because they have been convicted of criminal acts. Some people

208. Oral Johnson
return and continue illegal activities such as drug trafficking and other criminal related
activities.
 Broken families – A major problem caused by emigration is that a number of children are
left with relatives as their parents seek a better life. Children who do not live with their
parents on a regular basis tend to develop more social problems than the average. For
example their education is likely to suffer and they are more likely to be involved in
crime.
Diaspora – This is the dispersal of people from a particular country around the world. The
number of Jamaicans living abroad is estimated to be about 2.6 million. This is almost the
same as the population living in Jamaica at present

209. Oral Johnson
Economic Activity
The term “economic activity” refers to any activity which produces a good or service. People
earn a living by engaging in various economic activities. Though people engage in thousands of
different economic activities around the world, they can all be classified into three major groups:
Primary Industry:
These are industries which take natural resources from the earth. Because of this they are also
called extractive industries. Examples include farming, fishing, forestry, mining and quarrying.
The products of some primary industries, such as fishing or agriculture, can be used as they are.
The fishermen go to sea and come back with the fish they sell directly to the market. The
products of other primary industries, such as bauxite and crude oil, are used as raw materials for
other industries. For instance, oil from Trinidad and Tobago is exported to companies in the
USA where it is used to make petroleum products. Some developing countries employ more
people in the primary industry than any other type of industry. For instance 80% of Egypt’s
population work in agriculture.
Secondary Industry:
These industries are involved in the production of processed goods. Many take raw materials
from primary industries and use them to make products for sale. Others use goods provided by
other secondary activities and process them to complete their finished product. For example in
car manufacture the factory where the car is put together is supplied with parts by other factories
that specialize in making wheels or seats or windscreens. Examples of secondary industries
include clothing manufacture, oil refining, automobile production and food processing.
Secondary industries are also called manufacturing industries and almost always use some kind
of factory.
Tertiary Industry:
These are industries which provide a service. Because of this they are known as service
industries. Unlike primary and secondary industries, they do not make goods that can be seen or
handled. Instead they include employment in education (teachers), the police, fire service,
healthcare, public transport, local government, banking and finance. Two of the biggest
Caribbean employers, tourism and retailing, are included in the tertiary sector.

210. Oral Johnson
In many countries it is the tertiary industries that now employ the majority of the population. In
Jamaica, 68% of people work in the service sector (tourism). In the UK 74% of the people are
employed in the service sector. Activities are largely based around health, education, retail and
the financial sector.
Most developing countries, unless they have a highly developed tourist industry, have a low
percentage of people working in the tertiary sector.
Quaternary sector
Quaternary activities, or quaternary industries, are fairly new addition to the classification of
economic activities. They are often thought of as just another part of the tertiary sector because
they also provide a service. The difference is that the quaternary sector mainly concentrates on
those industries that provide information and expertise. This includes activities such as training
and research and development and includes high technology industries such as internet-based
companies.
Because many of the quaternary industries rely on new technology such as satellites and
computers they do not have to be located near to their raw materials in the same way as drilling
for oil has to be. They can, therefore, move to areas either where wages are lower or where there
is a pleasant environment for their employees to live and work in.
Several companies in the quaternary sector are now setting up in the Caribbean for those reasons.
Call centres, where people ring up for advice on their bank accounts or for help in booking
airline flights, are a good example. The customer never gets into direct contact with the
employee they talk to on the phone, so it makes no difference whether the company is located in
Guyana, India or the UK.

211. Oral Johnson
Examples of Primary Sector in the Caribbean
While agriculture remains a traditional way of earning income and a vital part of a sustainable
economy, it has given way to tourism, mining and drilling as a mainstay of the Caribbean
economy.
AGRICULTURE
Caribbean nations produce and export bananas, citrus, cocoa, sugar cane, mangoes and coconuts.
MINING AND DRILLING Petroleum, natural gas, bauxite, gold and asphalt are some of the
underground natural resources that attract mining and drilling interests. Jamaica and Guyana
have gold and bauxite reserves, and Trinidad and Tobago has extensive drilling operations in
petroleum, natural gas and asphalt.
Forestry- Guyana, Belize, Bahamas, Dominica
Fishing- Cuba, Belize, Guyana, Netherland Antilles
Bauxite Mining – Jamaica, Guyana, Suriname
Oil – Trinidad
MANUFACTURING
Food processing is one of the oldest industries in the Caribbean. It was established during the
colonial period. The products are highly dependent on local and regional markets, some of which
are niche markets being exploited internationally. The medium and large enterprises produce
beverages such as beer, rum and soft drinks, utilizing local raw materials as well as imported raw
materials and semi-processed materials. For example, the distilleries in Jamaica and Trinidad and
Tobago.
TOURISM
Tourism is big business in the Caribbean where several countries depend on revenue from
foreign visitors. Tourists visit the Caribbean to experience the exotic, natural beauty and sand,
sea and sun. Caribbean nations frequently capitalize on historic landmarks, nature and festivals
to attract tourists while constructing infrastructures to accommodate them. Jamaica, Barbados,
Trinidad and Tobago, The Bahamas, the British Virgin Islands, the US Virgin Islands,

212. Oral Johnson
Martinique, Guadeloupe and Grenada are the Caribbean nations that have well-developed
tourism
Explain the relative importance of primary, secondary tertiary activities in the Caribbean
Benefits
- One of the most important importance of economic activities is that they all create jobs.
People with jobs pay taxes to the government which uses this money for services such as
health and education.
- They are also a source of foreign exchange. When goods are exported countries receive
payments in international currencies such as US, Euros and UK pounds.
- All governments need foreign exchange to pay for goods and services from overseas.
Money paid for exports will often be in US dollars and this is useful for governments that
want to buy things from other countries.
- Provides food and goods for human consumption, and service. Agricultural produce are
consumed daily.
- Governments also take money in taxies from companies and business operating in their
country. This money can be spend on the infrastructure, such as roads, port services and
education for people. A better infrastructure will attract more foreign investment into the
country.
All four types of economic activity are important to the islands of the Caribbean but their relative
importance varies from place to place and changes over time. Nowadays, almost all the
Caribbean islands have a well-developed tourist industry in the tertiary sector. However, a
hundred years ago only a few very rich visitors from Europe and North America would have
contributed to this part of the economy.
Up until the middle of the 20th
century, most of the Caribbean’s income came from the primary
sector, mainly from agriculture and large estates producing valuable crops such as sugar, bananas
and nutmeg. As countries become more economically developed, fewer people work in
agriculture and secondary and tertiary activities become more important. In the Caribbean, these
include:
- Garment manufacturing in St Kitts and Nevis, food processing and the drinks industry in
Jamaica, electrical goods in Barbados and cement manufacture in Guadeloupe.

213. Oral Johnson
- Tourism in Jamaica, Puerto Rico, Dominican Republic and many other Caribbean
islands.
- Financial services in Bermuda, the Cayman Islands and the Netherland Antilles.

214. Oral Johnson
Renewable and Non- renewable resources
Renewable resources- Any natural resource that CAN be replenished naturally with the passage
of time (e.g. wood, solar energy, wind energy and forestry).
Non-renewable resource- Any natural resource that CANNOT be replenished with the passage
of time. They’re exhaustible. Examples in coal, oil, gas, bauxite and gold.
Areas in the Caribbean with the following resources
Forests- Belize, Guyana, Bahamas, Dominica
Fish- Belize, Guyana, Bahamas, Dominica and Cuba
Limestone- Jamaica, Barbados, Puerto Rico
Petroleum/oil- Trinidad and Tobago
Natural Gas- Trinidad and Tobago
Bauxite- Jamaica, Guyana and Suriname
Industrial Location in the Caribbean
Factors affecting industrial location
Industries that are involved in processing raw materials or manufacturing new products such as
cars, computers and clothes form the secondary sector of the economy. Most industries have very
specific needs, which affect their location. These needs are called locational factors
Physical factors
Raw materials
Heavy and bulky raw materials, such as sugar, coal and bauxite, are expensive to transport.
Industries involving these raw materials are often located close to the source of raw materials.
Bauxite plants in Jamaica are located close to the bauxite deposits.
Energy

215. Oral Johnson
In the past, industries were tied to power sources such as coal and water. Today most industries
use electricity, which is available almost everywhere at the flick of a switch, so this factor is less
important than it used to be
Relief
Industries often need extensive areas of flat land for building of infrastructure and storage
buildings. It’s easier to build infrastructure on flat or gently sloping lands
Political
Government policies
Governments often encourage industrial location in certain areas by providing grants or tax free
incentives. The government of Jamaica has established Free- Trade zones to encourage industries
to locate there. Other countries have used this strategy to invite industries to develop in specific
areas.
Human/Economic
Labour
Factories often need to employ large numbers of workers and for this reason it is an advantage to
be located in a town or city. Some industries require highly skilled university-educated workers.
In the Caribbean most of the garment industry are located in the capital cities (urban areas). This
industry is labour intensive and hence requires a large number of people. Therefore they locate in
these areas that usually have a high population.
Transport
Good transport links are essential for many industries to bring in a raw materials and take away
finished products. For this reason many industries are close to main roads, railway terminals or
ports. E.g. the garment and food processing industries are located close to ports as they
sometimes are largely dependent on imported raw materials.

216. Oral Johnson
Capital- industries rely upon investments in buildings, equipment and training. This may come
from governments or wealthy individuals and can affect location. If money is borrowed from the
government, the government can influence where the industry should locate.
Markets
Industries need markets for their products. Some industries in the Caribbean export their
products to nearby countries such as United States e.g. one of the main markets for Caribbean
Bauxite is the United States. In addition the local population in countries are often markets for
different products e.g. clothes and processed food).
Primary sector case Study: Fishing in the Caribbean
Fish are abundant in the warm waters of the Caribbean and have always been an important
source of food. Most countries in the Caribbean have developed small scale fishing industries. In
some countries it is exported and provides foreign exchange and contributes to the GDP.
Importance of fishing industry
 The industry provides jobs. Over 10,000 persons are employed in Guyana and several
thousand persons are employed in Barbados and Trinidad and Tobago.
 Provide raw materials for further processing. E.g. Canned Tuna or Mackerel
 Provides a source of foreign exchange when products are exported and directly
contributes to the GDP of the country.
 Provide food for consumption ( a direct source of protein)
Fishing in Belize
Belie has one of the best fishing grounds in the Caribbean and Fishing make up 6% of GDP.
Over 1,672 persons are employed in fishing, most belonging to a small number of cooperatives
that own the modern-fish processing plants. The most important fish products are lobsters, conch
and shrimp. Lobsters are caught in wooden traps or by divers in the shallow waters along the

217. Oral Johnson
coral reefs (account for over 50% of the export earnings). Conchs are found on beds of sea grass
and shrimps are caught by trawlers.
Factors influencing the location of fishing industry in Belize
Belize fishing industry is located on the coast (coastal fishing). This is due to several reasons.
 Belize has productive fishing grounds. Rivers bring nutrients to the sea. The shallow
waters offshore hold nutrients for marine life. Mangroves and sea grass beds in shallow
water provide food and shelter for young fish. There are barrier and island reefs where
living coral, fish and crustaceans thrive. The barrier reef is over 290km long. They are
also fishing grounds in deeper water, beyond the barrier reef
 There are several sheltered harbours and ports that are able to facilitate fishing vessels
and export products (processed fish).
 The communities on the coastline are organized for commercial fishing. There are close
to 2,000 fishers, and many shore based jobs in processing and administration. Fishing
cooperatives are located in these coastal communities. Close to 60% of the fishers belong
to a fishermen’s co-operative. The co-operative buys the catch from the smaller
fishermen, process it, and exports it by sea to the USA, with also to Europe and Japan. At
the end of the year, the profits are distributed to members as a second payment.
Challenges and problems of the fishing industry.
A number of challenges face the Caribbean fishing industry:
 Overfishing, this often involves catching and killing young fish which cannot then mature
and breed. This reduces fish stocks and is unsustainable.
 Pollution is also a problem. Rivers and seas are polluted by oil and sewage waste. This
can contaminate fish and kill off fish stocks.
 Mangroves and other breeding grounds are sometimes destroyed to facilitate tourism and
residential development.
 Global competition from big fishing businesses from countries such as Japan with high-
tech equipment used, for example, to track fish by satellite.

218. Oral Johnson
 Similarly like agriculture there is a reduction in labour as young people do not want to
enter the fishing industry.
 Some widely available species are under-used at the moment
Solutions
 There is a closed season for conch from July to September, and for lobster from February
to June, when most breeding takes place. This allows the
 Young lobster and conch below a minim minimum size are not used. This gives them a
chance to mature. Conch shell must exceed 7 inches.
 Scuba diving for conch and lobster is not allowed. This prevents diving in water over
15m deep,
 Each co-operative has an annual quota
 Fishing for grouper is prohibited in most places, because over-fishing has damaged
stocks
 Government is also trying to encourage individuals to make greater use of the less
popular under-used species.
Bauxite mining in the Caribbean
Case study: Jamaica
Bauxite is the ore from which aluminum is made. Jamaica contains some of the largest known
deposits of bauxite in the world. The mining areas are located in the western and central parts of
the island. After mining, most of the bauxite is carried to alumina plants where it is refined into
alumina. The alumina (or in some cases unrefined bauxite) is carried to export ports by rail. Most
of Jamaica’s bauxite is refined into alumina and the rest is exported unrefined. The marketing of
bauxite and alumina is done by large international companies
Other producers of Bauxite in the Caribbean includes Guyana and Suriname. In 1965, these
produced 44% of the world’s supply. Other major producers include Brazil, China and India.
Australia is the world’s largest producer of bauxite. The bauxite industry provides job to millions
of people across the world and is a major foreign exchange earner for several countries.

219. Oral Johnson
Factors that influence the location of the bauxite industry in Jamaica.
The bauxite plants (alumina plants) in Jamaica are located close to the bauxite deposits. The raw
material which is bauxite is heavy and very expensive to transport. Hence the industries are
located to the raw material to minimize transportation costs. The parishes with the largest
quantities of bauxite in Jamaica includes St Ann, Manchester, Clarendon, St Catherine and
Trelawny. Jamaica’s bauxite occurs in shallow pockets across the central portions of the island.
Bauxite plants have developed close to these deposits in the parishes mentioned above.
Good transportation networks (roads and railways) were built to transport bauxite and the
processed alumina to ports to be exported. The alumina is then exported to nearby markets such
as US where it is further processed into Aluminum. The closeness to the major market in the
USA is important as transportation costs are less. Large capital invested from overseas
companies further developed the industry.
Challenges faced/problems of the industry
 Jamaica is finding it more and more difficult to compete with other bauxite producers
around the world. Countries such as China, India, Australia and Guinea have become
important bauxite producers. Australia, Brazil and China have lower-quality bauxite, but
cheaper and sometimes more reliable supplies.
 Also, aluminum smelters have been built in Europe, Asia and South America. North
America is no longer the major producer of aluminum.
 Output per worker is lower and their wages are higher than in other countries. The cost of
mining bauxite is therefore expensive. Large international companies play a leading role
in the Jamaican Bauxite industry. They use Caribbean bauxite and alumina for their
plants in other countries. Shipping costs are now lower and so transport costs have
dropped. This has caused mining costs to become a more important factor than location
near a smelter. The mining cost is high, so companies may eventually switch to other
mines where mining cost is lower.
 There is an over-reliance as most countries major market is the USA. If any economic
situation should occur in the country for e.g. if demand is reduced, this would
significantly affect the country’s export volume and ultimately it’s GDP. Reliance on one
country is problematic.

220. Oral Johnson
 Alumina plants use caustic soda to remove impurities from bauxite. The process produces
‘red mud’, which is 20% solids and 80% liquid. For each tonne of alumina, there are up
to five tonnes of red mud, which is dumped in ‘ponds’, covering up to one square km.
Caustic soda in the red mud kill nearby vegetation. In dry weather, crystals form on the
surface; when these blow away, they make the air unpleasant to breathe. If it escapes,
contaminated water from red mud ponds can pollute springs and wells.
 Vegetation is destroyed to facilitate the building of roads and railways to transport the
bauxite.
 The mining of bauxite requires several equipment such as tractors, trucks, mechanical
excavators and conveyor belts. They are powered by fossil fuel based energy sources
particularly gasoline/oil (gasoline comes from oil). Whenever these fossil fuels are burnt
they release harmful gases in the air such as carbon dioxide, methane and nitrous oxide.
Solutions
 There has been some progress in dealing with red mud. Improved technology in alumina
plants produces a more concentrated mud. There is less to dispose of. In addition drains
underneath red ponds extract caustic soda, which is recycled in the alumina plant.

221. Oral Johnson
Food processing in CARICOM and Hong Kong
Development of manufacturing industry in Hong Kong
Hong Kong is art of a newly industrializing country (NIC). While it retains some features of a
developing country, its economy is expanding and standards living have improved. Hong Kong
is a former British colony and it developed as a thriving port and as a gateway between the west
and Asia. In 1997, it reverted back to being part of china, although today it still retains a very
distinctive and Westernized character.
Factors that influenced the location of and development of Food processing in Hong Kong
Hong Kong has long been involved in Trading. The port facilities are very developed. The food
processing industries are located close to these ports to facilitate easy importing and exporting.
Unlike the Caribbean that processes local products Hong Kong depends entirely on imported raw
materials. In addition in the major coastal cities there is a large and relatively cheap labour force.
Its closed link with mainland china provide a huge nearby market for processed foods. It has a
tradition for producing entrepreneurs and successful business people to create and run industries.
Its extensive port facilities, relatively large and cheap labour as well as easy access to the
Chinese market have influenced the location and development of the food processing industry
in Hong Kong.
Food processing in Hong Kong
Food processing is one of Hong Kong’s most successful and fastest growing industries. In 2008,
there were 786 factories employing 26,600 workers.
Much of the exported-oriented with the main markets being mainland china. It also exports to
Taiwan and Macau. It is very DIFFERENT from the Caribbean where food processing involves
products actually grown in the Caribbean. In Hong Kong, raw food is imported and then
processed before being exported.
Hong Kong manufacturers process a wide variety of foods and drinks for three main
markets.

222. Oral Johnson
1. Local consumption in Hong Kong- this includes fish processing, noodles, biscuits,
seasoning, and dairy products. With a population of nearly 7 million persons, the home
market is an important one for the food processing industry
2. Chinese Mainland (China) - the most popular items include bird’s nest, mixed oils and
processed duck. Hong Kong is considered to be the major gateway through which the
Chinese mainland’s demand for western food is met.
3. Foreign markets (Asian and Western) - popular products include dried noodles, oriented
foods and sauces, such as soy sauce and oyster sauce.
Recent Trends and Future challenges
1. The industry needs to be constantly adapting to changes in the Chinese market. With
people living longer and more women adapting to choosing to follow careers, there is less
time for food preparation and shopping. Customers are increasing looking to buy ready
meals and frozen products
2. Demands are increasing for healthy products, such as low-cholesterol dairy products as
well as low-sugar and low-salt items. Many companies are now producing health options
or dietary products as part of their increasing range. Demand for energy drinks has soared
in recent years
3. In the face of increasing competition some Hong Kong companies have started to set up
factories and offices in export market centres such as the USA, UK and Australia to
secure their market position.
Food processing in the Caribbean
Food processing is an important manufacturing industry in the Caribbean. Food is processed
to preserve it and to add value before it is sold. A wide range of agricultural products are
processed in the Caribbean including sugar cane, cocoa, citrus fruit, fish, meat, nuts and
preserves of local fruits. Processing involves canning, drying and smoking. The industry
employs several thousand workers across regions.
Factors that influence the location of food processing in the Caribbean

223. Oral Johnson
Raw material- There are different types of products are that are processed in the Caribbean.
These cases below shows how raw materials influences industrial location in the Caribbean.
Sugar and rum are products that are formed from the processing of sugar cane, the sugar cane
refineries in Jamaica are located close to where the sugar cane is grown. The Rum factories
are also located close to the sugar refineries. This is because the raw material is bulkier and
more expensive to transport than the finished product (bottles of rum).
This is a similar case in Guyana with their beef industry. The processing factory is located
close to cattle farm (ranch) in Lethem. This is because the raw material (cattle) is heavy to
transport so the location of the industry is close to the raw material. The processed beef is
sold locally and also exported to nearby Brazil.
Transport and Labour - In other cases food processing industries in the Caribbean are
located close to ports or have coastal locations. These are import-export industries. They
import the raw materials and process them near the port. After processing they export the
final product. In the Caribbean ports are usually located in major cities where processing
industries also benefit from an urban work force and a large domestic market. E.g. There is
a flour mill in Kingston Jamaica. It is located close to the Kingston Harbour (port). The
Flour mill processes imported flour, which explains its port location. They benefit also from
the urban workforce and a large domestic market. They export to other Caribbean countries.
In Guyana, food processing is also located close to the coast. This is because the capital
Georgetown and other coastal towns provide a workforce and a large domestic market. The
ports also enable processed products to be exported. The raw materials are also located close
to the coastal areas as well.
Recent Trends and future challenges
 Increasingly, Caribbean food processing is based on imported raw materials. For
example, in Barbados powdered milk is imported from New Zealand processed into
condensed milk, evaporated milk and yoghurt.
 While there are some large factories in the Caribbean, a lot of small- scale cottage
industries exist often employing less than 10 workers.

224. Oral Johnson
Comparing food processing in the Caribbean with Hong Kong
Caribbean Hong Kong
Types of products
produced whether local or
imported
Processing both locally
produced foods and
imported products
Mainly processing
imported products
Products Sugar, rum, fruit, nuts,
coffee, cocoa, fish,
sweets, juices and
seasonings and dairy
meat
Fish, sauces, duck,
noodles, pasta, seasonings
Location Close to raw materials (
sugar cane, cattle farm),
coastal sea ports
Close to port facilities for
import/export
Labour Local Local, relatively cheap
Markets Caribbean and USA Mostly mainland China
Recent Trends/Challenges Changing market forces
and demand for healthy
products, organics etc.
Changing market forces
in China requiring healthy
products, ready meals and
western foods.

225. Oral Johnson
TOURISM IN JAMAICA
Tourism is an example of a service industry or a tertiary industry
Tourist season: December- April Origin of tourists: USA, Canada, and Europe
BENEFITS OF TOURISM TO JAMAICA
 Foreign exchange- Tourist spend their money in US dollars, euros and British pound
which provide an important source of revenue. Tourism is the largest earner of foreign
exchange. Earnings from tourism accounts for 15% of the GDP of the country. The
money can be spend on education, health and also paying for imports.
 Employment – Man persons are directly employed in the tourist industry such as tour
guides, waiters, cooks, cleaners, chefs and receptionist. Indirectly, many persons gain
employment too, for example, in construction, food supply, electrical and plumbing,
transportation (taxis, bus tour operators, car rental agencies), craft vending and
entertainment (music, singers and dancers)
 Improvement in infrastructure- tourism has many useful knock-on effects on the
economy such as improvements in infrastructure (roads, airports, electricity and water).
 Many countries charge a departure tax or a head tax for visitors and this money goes to
the government to help pay for things such as electricity and water services, roads, health
and education. An airport departure tax of US$35 is payable when departing Jamaica. In
most cases this tax is included in the cost of the airline ticket (paid in advance).
FACTORS INFLUENCING THE DEVELOPMENT OF TOURISM
PHSYICAL FACTORS
Climate- The Climate in the Caribbean is stable, it is warm and sunny all year round. The tourist
season (December to April) also falls out of the hurricane season. It is very cold in North
America and Europe at this time of the year. As a result of this tourists visit the Caribbean to
escape the extreme temperatures in their homelands. This is one of the major factors influencing
the development of tourism in the Caribbean

226. Oral Johnson
Natural Attractions – Beaches and sea, natural scenery
There are excellent white sand beaches in the Caribbean which are well maintained and the water
is warm and crystal clear. As a result water related tourist activities are common in the Caribbean
for e.g. snorkeling, swimming, sailing and glass bottom boat rides which allow them to see the
beauty of underwater life. There are also natural features such as caves, waterfalls and
mountains which attracts tourists. The natural water falls e.g. Reach falls (Portland), Dunns’s
River (St Ann) and Y.S falls (St Elizabeth) are used for recreational activities. The Blue
Mountain and the Cockpit Country are world heritage sites, most of its natural vegetation is
untouched. Tourists do nature walks in the mountains. Erosion of limestone rocks has produced
huge underground caves with stalactites and stalagmites for e.g. The Green Grotto Caves in St
Ann
Accessibility (Geographical Location)
Jamaica is located near to the large tourist market of the USA. There are direct flights linking
Jamaica with the major population centers of the USA and Canada allowing easy movements of
tourists. Cruise ships (especially from the USA) also bring tourists to the island.
Human and Economic Factors
Culture- The culture of the Caribbean is very diverse and unique. It is dispersed across the world
by the millions of migrants from the Caribbean. Our cuisine, music and art is world-renowned
and tourist visit the islands because of this. A traditional place is the Bob Marley Museum in
Kingston. The reggae sumfest also attracts a lot of visitors. The annual Crop Over festival in
Barbados and Carnival in Trinidad attracts many visitors to these countries. Jamaicans are also
seen as friendly with good hospitality.
History- Many historical sites and buildings are in Jamaica that also attracts tourists. E.g. include
Rose Hall Great House, Devon House, old forts, old cathedrals etc. Visitors can visit these sites
to learn about the history of the country.
Education - Skilled Workforce There are many institutions which offer training for employment
in the tourist sector for e.g. Heart Academy, UTECH and UWI. Tourism and hospitality
management is a course that is offered by both UTECH and UWI. Every year hundreds of

227. Oral Johnson
students pursue the course. Upon completion of the course students are employed directly by
hotels and other tourism organizations.
Government Encouragement
The Jamaican Tourist board is responsible for selling Jamaica to the world. They advertise the
attraction of Jamaica abroad. There are also offices in North America and Europe. Advertisement
is also done on social media pages through the Jamaica Tourist Board. Brochures and pamphlets
can be seen around many major airports across the world.
In addition the government has improved facilities for tourists by upgrading facilities in resort
areas e.g. road, high ways (North Coast High way) and docking facilities for cruise ships e.g.
Falmouth. Most of the hotels that are here in Jamaica are multinational companies ( Riu, Secrets,
Iberostar, Grand Palladium). They’re Spanish-based hotels and are owned by international
companies. In order to attract these hotel chains into the country the government gives generous
incentives such as tax breaks (10yrs-50yrs). The hotel chains will not nay pay tax for the
specified time given.
Challenges/problems faced by the Tourist industry in the Caribbean/Jamaica
Competing destinations
Jamaica was one of the first tropical islands to develop its tourism product. Today there are many
other well established tropical destinations in the Caribbean and elsewhere. It is now more
difficult to make Jamaica stand out when there are so many tropical islands to choose from.
Export of Profit/All-inclusive resorts
Sometimes money earned by tourist industry does not remain in the Caribbean because the
resorts may be owned by foreign companies which take their profits overseas. In Jamaica for
example, there are many Spanish hotels on the north coast and the profits earned by these hotels
are therefore taken out of the country. Out of every dollar (100cents) that is earned through
tourism 43 cents is retained by the country and the rest goes to the overseas companies.
Large import content

228. Oral Johnson
Majority of the products that are used in the tourism industry is imported for e.g. food and other
infrastructure. The local economy is not able to provide the large quantity of products for some
foods on a consistent basis. Therefore significant of money is loss through this means. This is
called import leakages.
High levels of crime and violence
Tourists are often harassed by local people who want to sell them just everything ranging from
local craft items to illegal drugs. Sometimes crimes are committed against them and all of these
factors cause them to go to other tourist destinations where these problems are not encountered.
If a country is unstable and there is crime and violence this will discourage visitors. Good
examples include the Tivoli incursion and the upsurge of violence in Montego Bay. United
States advised its citizens not to visit the country. This can have a significant influence on the
economies of Caribbean countries that are dependent on tourism.
Increase in cruise passengers
An increasing number of persons are now taking cruises rather than land-based vacations. Cruise
passengers spend less money on shore than those in hotels do. In some cases tourist don’t leave
the ship at all. Everything is available on the ship. No money is spent in the visiting country
when this happens. The country therefore earns less from cruise passengers than from those who
opt to stay in hotels.
Economic dependency / over dependency on tourism
Some countries are too dependent on tourism and this can be a problem. Majority of the tourist
that visits Jamaica comes from USA. During economic crisis such as recessions people will more
likely to save money rather than spend on extravagant holidays. This happened before and the
number of visitors declined significantly.
Environmental damage
Tourism is beneficial to the economy of the country but it also has significant consequences on
the environment. Large areas of vegetation for e.g. mangroves are cleared to facilitate the
construction of hotels. Tourist sometimes when doing activities such as snorkeling or diving may

229. Oral Johnson
trample corals or take corals for souvenir purposes. Large cruise ship sometimes drop their
anchor on coral reefs and dispose waste directly into the ocean.
Solutions
Tourism in Jamaica is dependent to a large extent on what the natural environment has to offer
e.g. the beaches, sea, rivers etc. Unfortunately there are various activities associated with tourism
which have resulted in these resources being downgraded. Efforts are therefore now being made
to ensure that our tourism remains a sustainable type of development. Sustainable tourism
ensures that the country’s resources not destroyed, but they remain intact so they can be used by
future generations.
Ecotourism- In effort to preserve the environment, several Caribbean countries (including
Jamaica) have been encouraging the development of ecotourism. Ecotourism refers to a type of
tourism which caters to visitors who are interested in the natural beauty of a country’s natural
environment and/or its wildlife. Eco tourists have interest in activities such hiking, bird
watching, visiting rainforest etc. Inn areas where ecotourism is promoted, the environment is
conserved, while at the same time providing employment opportunities for the local people.
Examples of such trips include:
 Building bamboo rafts to see the rainforest along the Rio Grande
 Island-wide bird watching trips to find all 27 of Jamaica’s native bird species, including
the Jamaican owl, Jamaican mango and Jamaican today.
Ecotourism often involves the setting up of Eco lodges in nature reserves, rainforest areas or
isolated beaches where they are built to fit in with the natural environment. Instead of huge hotel
complexes, guests normally stay in small cabins, often with no electricity, and eat local food.
Guides may take them on walks to understand the local environment. Eco lodges employ a large
number of local people and have a small impact on the environment.
Heritage tourism- This type of tourism focuses on using the history and culture of a people as an
attraction for tourists. Activities include historical buildings, museums, traditional rural
communities etc. Increasingly Caribbean are investing in this type of tourism as it does not result
in any damage to the environment

230. Oral Johnson
Agriculture
Classification of Agriculture
Farms can be categorized according to what is being grown or reared, the size of the operation
and the agricultural techniques being used.
For example, farming can be:
 Subsistence or commercial
 Arable, pastoral or mixed
 Extensive or intensive
 Sedentary or nomadic
SUBSISTENCE, PEASANT OR COMMERCIAL
Subsistence farming is the provision of food by farmers only for their own family or the local
community- there is no surplus. Subsistence farmers often produce the widest range of products,
and may include both the growing of crops and rearing of animals. The fact that subsistence
farmers are rarely able to improve their output is due to lack of capital, land and technology, and
not to a lack of effort or ability. They are the most vulnerable to food shortages.
Peasant farming is small-scale farming (slightly larger than subsistence farming) for
subsistence purposes as well as for cash sale in the market. Some of the crops grown include
sugar cane, bananas, cocoa, rice, vegetables and root crops. The famer may also rear animals to
supplement income.
Commercial farming takes place on a large scale, and its purpose is to produce crops or animals
for sale, whether locally or internationally. Monocropping or monoculture (the growing of one
crop exclusively) is a common feature of commercial agriculture in the Caribbean, especially
crops such as sugar cane or rice. Commercial farms are usually large.
ARABLE, PASTORAL OR MIXED

231. Oral Johnson
Arable farming is the growing of crops. Crops are plants that are harvested from the ground to
be eaten or sold. These are usually grown on flatter lands where soils are of higher quality.
Pastoral farming is the raising of animals usually on land which is less favorable to arable
farming (i.e. colder, wetter, steeper and higher land). However, if the grazed area has too many
animals on it, its carrying capacity is exceeded or the quality of the soil and grass is not
maintained and then erosion and desertification may result.
Mixed Farming is the growing of crops and the rearing of animals together.
Shifting cultivation or slash and burn is one other type of farming where farmers shift their farms
from one plot to another every few years. In this type of farming, there is limited input in the
form of fertilizers, so farmers rely on the restoration of fertility during the fallow. This farming
type can be considered a sustainable form of agriculture in areas where it does not put undue
pressure on the land; that is, where there is a large land area available plus a low population.
SEDENTARY OR NOMADIC
Sedentary farming is when a farm is based in the same location all the time.
Nomadic farming is when a farmer moves from one place to another. This is common in some
less developed countries.
EXTENSIVE OR INTENSIVE
Farming is extensive or intensive depending upon the relationship between three factors of
production: Labor, capital and land.
In extensive agriculture, LAND is usually the largest component of the farming system and
output is generally high relative to the land area under cultivation.
Extensive farming is where a relatively small amount of produce is generated from a large area
of farmland.

232. Oral Johnson
In intensive agriculture, unlike extensive, land is the smallest component in the farming system
and output is generally high relative to the land area under cultivation.
Extensive agriculture
The Amazon Basin- shifting cultivation
The Canadian Prairies- Wheat Cultivation
Intensive Agriculture
The Ganges Valley- rice cultivation
The Netherlands- dairying, horticulture
Intensive farming is where a large amount of produce is generated from a relatively small area
of land. Inputs will be high to achieve a high yield per hectare. Inputs could be fertilizers,
machines or labour.
Physical, Human and Economic factors influencing/affecting Agriculture
Human factors
Land tenure
This is the rights a person has to the land. Rights range from complete ownership to squatting. IF
the land is owned, the farmer is able to make long-term investments such as the growing of tree
crops like cocoa, coconuts and coffee; the putting up of farm buildings and the making of farm
roads. Farmers who actually own the land which they work also usually find it easier to borrow
money for making improvements.
At the opposite extreme, squatters (people who occupy land without having a proper title or
rental agreement) have no guarantee of continued land use. Because of day-to-day uncertainty,
most squatters prefer to grow short-term crops such as corn, peas and other vegetables. They
have no incentive to improve the land, or to put up farm buildings. They often find it difficult to
get credit (borrow money). In Barbados squatting is not very common, but in other Caribbean

233. Oral Johnson
countries such as Trinidad and Tobago, Dominica and Puerto Rico, this type of land-tenure
occurs more frequently.
For other forms of land-tenure between outright ownership and squatting, it is clear that the
longer the terms of the lease the more secure is the farmer’s tenure. The more secure the tenure
the greater is the possibility of obtaining credit, and so the greater the likelihood of farm
improvements being made.
Inheritance practices
In some parts of the Caribbean farms are highly fragmented. They do not consist of a single
continuous piece of land, but are made up of several scattered plots. Land fragmentation is often
the result of inheritance practices. On the death of a farmer, the land is often sub-divided among
the heirs. The fragmentation of farm holdings has several disadvantages. Firstly, the farmer
wastes a lot of time travelling between the various plots. Secondly, an unusually high proportion
of land is taken up by field boundaries, and so does not produce as much. Thirdly, the small size
of the plots make it difficult for the farmer to use modern machinery.
In St Lucia the multiple inheritance system is found, whereby more than one member of a family
inherits title to the same piece of land. This family land system has been a hindrance to
agricultural production, for the owners are usually more concerned with their rights to reap
whatever crops they find on it rather than with the need to cultivate and improve the land.
The role of government
Governments can influence farmers towards the form of land-use they feel to be most suited to
the country’s needs. Thus a government may acquire and distribute land to people who are
willing and able to farm it. The governments of Guyana, Jamaica and Trinidad and Tobago have
done this to some extent.
 In Cuba, on the other hand, the government has taken away the farmers’ land and formed
it into state-owned farms.

234. Oral Johnson
 In Barbados, where land is in short supply or under pressure from other uses such as
housing and tourism, the government has implemented a land for the landless program,
where farmers may have access to farmland owned or leased by the government.
 The Jamaican Ministry of Industry, Commerce, Agriculture and Fisheries has signed a
25-year agreement with brewery giant Red Stripe for the lease of 247 hectares of land for
the mass production of cassava to be used in the company’s beverages.
 Governments can come to the help of farmers by providing them with loans and
insurance. Small scale farmers usually lack the capital to buy equipment and products
that can improve productivity. The National People’s Cooperative Bank (NPCB) in
Jamaica offer loans to small farmers. Agricultural loans may be used to purchase
inventory (livestock, machinery, plants), expand the business, or energy conservation
ventures.
Labour
Labour is needed for the preparation of the soil and for planting and harvesting crops. It is also
needed for the care of farm animals. On crop farms labour requirements vary with the time of
year. They tend to be greatest a planting time and at harvest
Changes in attitude to farming have also affected the Caribbean agricultural sector. Because of
the slave legacy associated with agriculture, many young people have stayed away from the
sector, and labour has been difficult to find especially on larger farms and plantations. This has
fueled the use of mechanization on these plantations. It has also affected what is grown, as crops
which are labour intensive, such as cotton, have been abandoned. The shortage of farm labour
has a tendency to become very acute during harvest time, especially on some of the larger sugar
cane plantations. Sometimes farm workers have been recruited from other countries. For
example, people from St Vincent and St Lucia, and many people from Haiti find seasonal
agricultural work in the neighboring Dominican Republic.
Historical Factors/Tradition
History can play a large role in determining what type of agriculture is carried out. In the
Caribbean, most agricultural production has been for export, since that was the role of the
Caribbean on a global scale. They were to produce food for the colonial countries of Europe.

235. Oral Johnson
Sugar was required and sugar cane was therefore grown on a large scale to meet those needs.
This has continued to determine what is grown and by whom on what scale throughout the
region.
Other small techniques and farming practiced by our ancestors are still carried out today.
Examples include planting peas and corn in the same hole and planting cassava and sweet
potatoes together. There may be other ways of doing things which could be more productive, but
tradition tends to prevail.
Economic factors
Markets
In this sense a market is a demand for a particular thing. Farmers in the more developed
countries of the world generally know what kinds of crops and livestock products are in demand
at a particular time, and plan their land use accordingly. In some of these countries the
government helps by setting up marketing boards. For example in the United Kingdom there is
the Milk Marketing Board, and in Canada there is the Wheat Board. These boards keep the
farmers informed of market trends. In many of the less developed countries marketing is not so
well organized. Consequently, farmers often have little idea of market requirements. There is
often difficulty in getting information to farmers in time for them to change their plans.
Distance from the market also affects agricultural land use, although less so now than in the past
because of the development of modern forms of transport. Generally speaking, very perishable
crops need to be grown near to their market, so that they can arrive in fresh condition. For
example, in Trinidad and Tobago the famous Aranjuez vegetable-growing district is
conveniently placed to supply the urban markets of northern-western Trinidad.
Capital
This is the money which is needed to buy such things as land, animals, seeds, fertilizers, tools,
machinery, etc. In some parts of the world small-scale farmers lack the capital needed to buy
these things, which are so necessary to enable them to produce more. In some countries the
government now plays an important role in providing agricultural credit (loans to farmers).

236. Oral Johnson
Physical factors
Soils
Most plants need soil order in grow, and so the mineral content of the soil, its depth and its
texture all can influence agricultural activity. are not only important for crop growing, but also
for animal rearing as farm livestock eat plants which grow in soil.
Soil depth can also influence agriculture. Deeper soils located on plains or gently sloping areas
are more fertile and productive than thinner soils located on steep slopes. Plantations in the
Caribbean are typically located in flat areas where soils are deep and fertile. E.g. alluvial soils
covering the plains of Jamaica provide suitable soils for sugar cane cultivation. Not only are
these soils fertile but they are able to retain water (retentive) making them ideal for sugar cane
cultivation. Thin soils on steep slopes are easily eroded. The Scotland District of Barbados is one
of those areas where thin soils have been badly eroded in the past. Volcanic soils found in the
islands of the Lesser Antilles are very fertile and therefore many small farms are located on
them.
Soil texture is also important. The best soils for crop growing. These contain both clays and
sands. They generally drain easily (do not become waterlogged) and are relatively easy to work.
Soils need to be deep enough to accommodate the roots of the plants, and to keep them firmly
rooted.
Relief/Topography
Relief has strong influence on type of farming system and types of crops grown. On flat lands it
is easier to use machinery and the soils are usually deeper and more fertile. Typically large
plains in the Caribbean countries e.g. Jamaica, Trinidad, are used for commercial arable farming
because flat land facilitates use of machinery which is necessary for commercial farming to take
place. Roads for transporting reaped crops as well as irrigation systems can be set up more easily
on flat land.

237. Oral Johnson
As a result, the largest plains in Jamaica are used for commercial cultivation of sugar cane while
hilly areas tend to be associated with peasant farming where farmers grow a variety of crops.
Steep slopes also restrict planting of crops as soils are thin and therefore relatively infertile,
leading to low yields. Steep slopes also limit the use of mechanization, reducing the possibility
of intensification of production. In some parts of the Caribbean steeply sloping hillsides have
been terraced in order to create flat land on which to grow crops, and also to reduce the risk of
soil erosion.
Climate
Climate can have an impact on the type of crops that are grown. Each crop requires specific
conditions in order to grow for e.g. specific temperature ranges and rainfall amounts. For e.g.
Sugar cane needs high temperatures throughout the year, with mean monthly temperatures not
falling far below 21o
C. It also needs plenty of moisture (the total annual rainfall should be at
least 1000mm). Sugar cane can only grow in these areas (sugar cane will not grow in polar
climates)
Seeds germinate and plants grow best at certain temperatures, in some parts of the world
temperatures are favorable to plant growth throughout the year. This is the case throughout the
Caribbean where the farmer’s activities are more influenced by the distribution of rainfall over
the year. In countries such as Canada, however, there are periods in winter when plants will not
grow actively because of low temperatures. Consequently the growing season is a very much
shorter one than in the Caribbean.
Other climatic factors which influence agricultural land use include wind and sunshine. Certain
crops are easily damaged by strong winds, and so ideally should be grown in sheltered areas. In
the Caribbean where hurricane damage is frequent farmers may opt for crops that grow quickly
or close to the ground in order to avoid wind damage from storms, or in flood prone areas they
may opt for free tree crops instead. Many crops need a lot of sunshine to in order to ripen. Other
crops grow best in shades.

238. Oral Johnson
Peasant Farming in the Caribbean
Characteristics
Location
In Jamaica, rural peasant farms exist in the white limestone plateau as in the Christiana Area, in
the Lluidas Vale, St. Thomas in the Vale in the Valleys of the Blue Mountain region.
Size of Farm
This type of farming is carried out by small farmers on a small scale. Typically, farms are small
in size i.e. less than 2 hectares. Sometimes farms may be fragmented and scattered. In Jamaica
where two-thirds of the hand are made up of highlands, about 80% of the farms are under 0.4
hectare in size.
Type of Crops grown
Multi-cropping is practiced. This means that a variety is grown and may include ground
provisions ( Yams and sweet potatoes), vegetables ( lettuce, carrots, cucumbers) and tree crops (
e.g. Ackee and breadfruit). Very often farmers also practise mixed farming, meaning that
animals are reared along with the growing of crops. There are many benefits to be gained from
growing a variety of crops. Intensive farming is practiced as farmers try to get the highest output
from the farm.
Labour
As most of the farmlands are small the family unit of labour is the main type of organization.
The peasant farming organization is a family economy. Family labour is used in such activities
as weeding, hoeing, reaping, harvesting and storage.
Tools used

239. Oral Johnson
Simple tools such as the hoe, fork and cutlass are used on farms. There is limited use of
machinery due to lack of capital. The farmer may instead use animal manure to keep the soil
fertile and mulching, to conserve moisture in soil
Capital Expenditure
Capital expenditure is very small or limited due to the limited returns from small size farms. This
also reflected in the simple tools used.
Ownership
Very often the farmer may not own the land that he farms, but is leased from a big landowner.
Marketing of produce
The produce from the farm is sold to vendors who then sell the food locally, in the open markets
found in most towns. In more recent times ‘non-traditional’
Problems facing peasant farmers in the Caribbean
- Praedial Larceny – On occasion thieves may steal crops or animals from farmers. As a
result farmers may experience severe financial losses. Peasant farmers are not able to
afford security systems such as security fencing and farms are not insured against such
losses.
- Size of farms- Because their farms are very small, it is often difficult for peasant farmers
to make a reasonable living. Indeed, in some countries they only work for part of the year
on their own farms. At other times they may make cash income by doing seasonal work
on nearby plantations. This is particularly the case in areas where sugar cane is grown on
plantations, there being a large demand for extra labour when the cane is being harvested.
- Lack of capital - Because of their low income many peasant farmers are unable to afford
better equipment such as modern machinery, chemical fertilizers and pesticides which
would help to improve their crop yields.
- In some areas peasant farmers are fragmented, and farmers may waste a lot of time
walking between their various plots of land.

240. Oral Johnson
- Peasant farmers generally occupy fairly poor quality land, and as a result crop yield are
often poor. The reasons for this are mainly historical. In Jamaica, for example, during the
time of slavery most of the best quality land in the lowland areas was taken up by
plantations. After emancipation those former slaves who wanted to start their own farms
often found that the only spare land available to them was very poor quality land in the
hills.
- Weather related problems- The weather can cause problems, especially the rainfall. In the
Caribbean this cannot always be depended upon to come when it is most needed and in
the desired amounts. Farmers can be damaged or even completely destroyed by droughts
and floods. In many parts of the Caribbean also, hurricanes are a threat, especially to
crops like bananas which are easily blown over by strong winds. In addition most
peasant farmers have no insurance protect against crop losses.
- Storage problems - Storage facilities for crops are sometimes inadequate. As a result, it is
not always possible to store those crops when they are in surplus which might be used
later when they are in short supply.
- Pests and diseases - Pests such as worms may destroy crops or cause low yields. Very
often, farmers cannot afford to buy pesticides to control the spread of these pests. In the
past serious disease have included Panama Disease and leaf spot disease (in bananas),
lethal yellowing (coconuts) and witches broom disease (cocoa).
- In some areas, roads are inadequate, and as a result farmers sometimes find it difficult to
get their crops to market.
Commercial/Plantation Farming in the Caribbean
Characteristics
Size
Plantations (sometimes called estates) are very big farms (over 200 Ha). They usually have
hundred and sometimes thousands of hectares of land under crops. (N.B 1 hectare= 2.5 acres
Type of crops grown

241. Oral Johnson
Plantations usually grown one type of crop. This practice is known as monoculture. Crops are
grown almost entirely for sale, and are very often intended for export. The benefit gained
from growing a single crop is found in the ability to grow the crop more efficiently because
whatever methods are used can be used for the entire farm e.g. the same fertilizers are
applied, same insecticides can be used. There are also disadvantages. The entire crop is
susceptible to the same diseases and pests and when prices fall the farms suffer.
Labour
A lot of paid workers are employed. Plantation crops require a great deal of labor, both
skilled and unskilled. It allows for a high degree of specialization. The employee fertilize
crops, drive trucks, tractors, and harvesters in addition to several who cut the cane by hand.
The labour is highly specialized. The factory also require work to be done by engineers,
supervisors, managers etc. In some Caribbean countries there is an increase in the use of
machinery as there is a shortage of local labour.
Capital
A great deal of capital is involved. This is needed to buy land and machinery, build housing
and roads, pay the workers etc. Many plantations have their own factories for processing
their crops, and this also involves a lot of capital investment. Some plantations have their
own light railway systems for transporting the crops from the field to the factory.
Scientific methods
Methods of cultivation are usually modern and efficient. Much use is made of artificial
fertilizers (chemicals to put on the land to keep the soil fertile and to improve crop yields),
pesticides (chemicals used to kill harmful insect pests and control diseases), and herbicides
(chemicals used to kill weeds). Aerial spraying is also practiced.
Technology/tools used
There is an increase in the use of machinery on some plantations. Mechanization is
increasing since there is a decrease in local labour. Some countries harvest/harvested cane
manually. A lot of plantations are using machines such as the combine harvester that reaps,
threshes and cleans sugar cane in one operation. Other machines are also used.

242. Oral Johnson
Ownership
Some of the estates are owned by multinational corporations/ foreign companies. In some
countries plantations have been nationalized (taken over by the government). In Jamaica,
Complant, a Chinese Firm paid a 9 million for the Monymusk, Frome and Bernard Lodge
factories. Most of Guyana’s farms are owned by the government
Marketing of produce
Sugar cane was initially marketed under a special agreement known as the Lome Convention.
This is ensured that the farms in Jamaica had a sure market for their sugarcane at a pre-
agreed price. In the recent past however the sure market has been lost because of the activity
of the W.T.O., that is the World Trade Organization. The WTO ensures that there is a free
trade where no country gets preferential treatment when trading with another country.

243. Oral Johnson
Sugar Cane Production in Guyana and Brazil
Sugar Cane Production in Guyana
Guyana is the largest sugar producer in the Caribbean Community. Sugarcane is grown in
several areas near the coast.
Temperatures are high all year round and the area receives about 2000 mm of rain each year.
This is good as sugarcane requires high temperatures and at least 1500 mm of rain annually to
thrive. Also, there are two rainy seasons and two drier periods. Therefore, there are two
sugarcane harvests per year. The sugarcane is allowed to grow during the wetter periods and
harvested in the drier periods.
The soil near the coast is deep and fertile. It is therefore suitable for growing sugarcane. Most of
Guyana’s population lives on the narrow coastal plain, providing the sugar estates with an
adequate supply of unskilled as well as skilled labour. The main road which runs along the coast
makes estates easily accessible and also provides the estates with access to other areas.
The fact that the estates are located near the coast makes it easier to export their finished product.
All sugar estates are located relatively close to one of the ports from which sugar is exported.
Sugar is transported by ship from Blairmont, Skeldon or Georgetown.
Characteristics of sugar cane Farming
Size/Acreage
Guysco is a state own factory owns eight (8) sugar factories and grows sugar on 470sq km of
land; which is a larger area than the island of Barbados. This is 47 000 hectares. The sizes of the
farms are very large.
Farming Practices:
The system of sugarcane cultivation in Guyana makes controlled flooding possible. Before
sugarcane is planted, the fields may be flooded for months. This kills so reduces the need for
herbicides. The flood also contains essential minerals and nutrients so reduces the need for

244. Oral Johnson
fertilizers. Parasites are used to reduce pest infestations so there is minimal use of chemical
pesticides.
The planting of sugarcane is usually done by hand. Cane is usually planted in beds to aid
drainage and this makes the use of machinery difficult. In some cases, the soil is too soft for
heavy machinery to operate. Heavy machinery is used in only a few places.
There are many canals which cross the sugarcane fields. Almost one eighth of the area of the
average sugarcane field is taken up by canals. This elaborate system of canals is used for
irrigation. These canals are also used for transporting the canes to the factories. Sugarcane is
transported in small flat bottomed boats (known as punts) from the fields to the factories.
Sugarcane is usually harvested manually. After the cane is harvested, the roots are sometimes left
in the ground to produce new plants. This is known as ratooning. This is done up to four times.
Then the fields are ploughed and replanted.
Technology:
Most of the sugar cane production in Guyana is done manually (by hand). The use of technology
is therefore limited. Mechanization is difficult. Cane was traditionally in cambered beds, which
slope to aid drainage. The layout of the beds makes it difficult to use machinery, and in some
areas the soil is too soft for heavy equipment. Heavy machinery is used in only a few places.
Labour:
It is important to note that much of the work involved in sugarcane cultivation is done by hand.
This includes planting and harvesting. Therefore sugarcane cultivation in Guyana can be
described as labour intensive.
Ownership:
Majority of the farms are owned by the government. Guysco is a state own factory owns eight
(8) sugar factories and grows sugar on 470sq km of land; which is a larger area than the island of
Barbados. Some sugarcane is also grown by independent farmers
Marketing Sugar:

245. Oral Johnson
Most of the sugar produced in Guyana is exported to Europe. Some is exported to the United
States. Some is sold to other CARICOM member states including Suriname, Dominica, Antigua,
St. Lucia, Grenada and Jamaica. These markets pay more than the world price, allowing the
sugar industry to remain profitable.
Sugar Cane in Brazil
Brazil is the largest exporter if sugar cane is the world. Brazil also exports ethanol which is a by-
product of the processing of sugar cane. In 2009 Brazil produced 671,395,000 metric tons.
Characteristics of sugar cane Farming in Brazil
Size/Acreage:
The farms in Brazil are very large. The area planted in 2007 was over 7 million hectares.
Farming practices
Brazil farming practices have changed significantly over the past few decades. Traditional
methods were once used. Planting and harvesting sugar cane was done by manual labour. When
it was close to harvesting the sugar cane fields were burnt. This was done to remove the leaves
and to drive away any potential poisonous animals. The sugar cane were then cut by hand.
The sugar cane production now is highly mechanized. Most stages of the production is done by
machines. From digging rows to planting the cane is done by machines. Harvesting the crop is
done by machines which eliminates the need to burn fields.
Sugar cane in Brazil share some similarities with Guyana. Application of pesticides on Brazilian
sugarcane fields is negligible and use of fungicides practically non-existent. Major diseases that
threaten sugarcane are fought through biological control, introducing natural enemies to fight
pest. Brazilian sugarcane needs fewer chemicals due to the innovative use of organic fertilizers
created during sugarcane processing. For instance, sugarcane mills recover residues called filter
cake (which is rich in phosphorus) and vinasse (loaded with potassium, organic matter and
other nutrients), which they use in place of traditional fertilizers.
Labour:

246. Oral Johnson
The increase in mechanization reduces the need for human labour. The use of machinery
increases productivity and it’s efficient. Human labour is still needed to operate the machines.
The individuals who once worked on the farm are trained by the Brazilian government how to
operate the machines. . They are now operating the various machines on the farms.
Technology:
The use of machinery in almost all aspect of the sugar cane production suggests that technology
is widely used.
Markets
Approximately 2/3 of the sugar produced in Brazil is destined for foreign markets. More than
100 countries around the world rely on sugar from Brazil. Some of the key export markets
include India, Russia, Iran and United Arab Emirates.

247. Oral Johnson
ENVIRONMENTAL DEGRADATION
Impact of tourism on the environment
 Tourism contributes to the physical destruction of the reef when tourists trample it during
sightseeing expeditions. Boats carrying tourists indiscriminately drop anchor, destroying
the reef structure. Local people also rob the reef to make jewelry, handicrafts and trinkets
from coral for the tourists.
 Tourists who go on activities such as hiking and trekking cut down trees to build fires.
For example, one trekking tourist in Nepal – an area already suffering the effects of
deforestation – can use four to five kilograms of wood a day. Tourists using the same trail
over and over again trample the vegetation and soil, eventually causing damage that can
lead to loss of biodiversity and other impacts. Such damage can be even more extensive
when visitors frequently stray off established trails
 Forests, mangroves and other vegetation are being cleared to facilitate the construction of
hotels, roads and other tourism facilities. The Caribbean tourism is concentrated on the
coast and valuable ecosystems such as mangroves are destroyed to facilitate tourism
development. Mangroves are often seen as unsightly obstructions to tourist interests.
They are viewed as mosquito-infested, muddy swamps holding back progress and hinder-
ing tourism development. In addition habitat loss occurs as ecosystems such as
mangroves provide a home for several marine species.
 Transport by air, road and rail is continuously increasing in response to the rising number
of tourists and their greater mobility. Other methods of transport includes cruise ship and
tour buses. All the above mode of transportation uses fossil based sources for energy.
Environmentally unfriendly substances such as exhausts, carbon monoxide, nitrous oxide
and carbon dioxide are released into the atmosphere causing air pollution.
 Faulty engine systems on cruise ships can result in oil spills. Oil spills are dangerous and
can have serious impacts on the marine environment. Because oil is thick, birds and other
marine animals may entangle causing death. Ecosystems such as coral reefs are affected
as sunlight will not penetrate through the oil.

248. Oral Johnson
 In areas with high concentrations of tourist activities and appealing natural attractions,
waste disposal is a serious problem and improper disposal can be a major despoiler of the
natural environment – rivers, scenic areas, and roadsides. Solid waste and littering can
degrade the physical appearance of the water and shoreline and cause the death of marine
animals.
 Hotels in the Caribbean have inadequate and improper sewage disposal systems. Hotels
sometime discharge their waste into nearby water bodies. Sewage often contains large
amount of nutrients such as nitrates and phosphates which causes eutrophication. Sewage
run-off causes serious damage to coral reefs because it stimulates the growth of algae,
which cover the filter-feeding corals, hindering their ability to survive. Eutrophication
also kills other marine organism as they are deprived of oxygen. . Wastewater has pol-
luted seas and lakes surrounding tourist attractions, damaging the flora and fauna.
 Golf course maintenance can also deplete fresh water resources. In recent years golf
tourism has increased in popularity and the number of golf courses has grown rapidly.
Golf courses require an enormous amount of water every day and as with other causes of
excessive extraction of water, this can result in water scarcity.
 Chemicals such as fertilizers and herbicides are used to maintain golf courses.
Sometimes the fertilizers may infiltrate into groundwater and contaminate it. It also uses
1500 kilos of chemical fertilizers, pesticides and herbicides per year
Impact of manufacturing industry on the environment
 All raw-material extraction whether mining, or drilling involves disruption of natural
ecosystems. Most manufacturing industries require huge land space for operations. Huge
acres of land are to facilitate manufacturing development. A good example is the bauxite
industry in the Caribbean. Lands are cleared to construct the actual manufacturing plant.
In addition lands are also cleared to make roads to transport the bauxite to the
manufacturing plant. Sometimes communities are destroyed to access bauxite deposits.
The open cast mining method used by the bauxite industry in the Caribbean require
complete removal of vegetation and top soil
 The destruction of forests have led to a decline in natural habitats the support wildlife. In
addition it has forced organisms to move further into the wild, exposing them to predators

249. Oral Johnson
and intolerable living conditions. . Consequently, some wildlife species have faced
extinction while several others remain highly endangered. In addition deforestation
contributes to global warming. Trees store carbon dioxide in their leaves. Whenever trees
are destroyed the excess carbon that was once stores is released into the atmosphere.
 Most countries use fossil fuel based energy sources to fuel their manufacturing industries.
Fossil fuel include coal, oil and natural gas. Whenever these fossil fuels are burnt they
release gases in the air such as sulphur. Carbon dioxide, methane and nitrous oxide. The
mining of bauxite requires several equipment such as tractors, trucks, mechanical
excavators and conveyor belts. The trucks used to transport the bauxite to the
manufacturing plant uses oil as their source of energy. Again several gases and pollutants
are emitted into the atmosphere
 Both surface and ground water, ocean and seas are affected. Industries release organic
materials, petroleum products, metals and acids into water systems. Jamaica’s
bauxite/alumina industry produces a waste product known locally as “red mud”. This
waste has been disposed of, for over 30 years since the plants were constructed, in
unsealed mined out pits. The red mud ponds are in the direct path of ground water flow
and pose a serious threat to ground water reservoirs and consequently the ground water
reserves of the island. Sometimes the waste go directly into nearby rivers and
underground water sources
Impact of agriculture on the environment
 Commercial farming (monoculture-one crop) can result in soil exhaustion. Some crops
such as corn use up more/demand more of a particular nutrient (for e.g. nitrogen. This can
reduce the fertility of the soil over time as the one nutrient is constantly being used up by
the crop. The problem is even worse if fertilizers are not being added to the land to
replenish the already depleting nitrogen nutrient.
 Commercial farming is a large scale farming which requires large land space. Vegetation
is usually cleared to facilitate this. This can have several impacts. Vegetation plays a
huge part in the storing of carbon. Once vegetation is cleared the carbon that was stored
is released into the atmosphere. This will accelerate the process of global warming. The
more carbon dioxide in the atmosphere the more heat that is going to trap.

250. Oral Johnson
 In addition clearing of forest can result in habitat destruction for some animals, reduction
in biodiversity and loss of some ecosystem. In many parts of the world the farmers drain
wetlands to create areas for farming. This can lead to the loss of ecologically important
wetlands such as swamps/ mangroves. By draining these important wetlands we are
destroying the habitats of many aquatic species.
 One of the characteristics of commercial farming is that there is usually large inputs of
chemical fertilizers (such as nitrogen and phosphorous). Fertilizer, in the form of mineral
compounds which contain elements essential for plant growth, is widely used to produce
a healthy crop and increase yields. If too much fertilizer is applied to the soil, some
remains unabsorbed by the plants and can infiltrate in the soil and contaminate ground
water. Increase in nutrients in ground water can result in a process called eutrophication
(algal explosion). The newly introduced algae will use up most of the oxygen which
deprive other marine plants and animals of it. This can result in massive death of marine
organisms such as fishes
 The agriculture industry in most countries especially for commercial farming requires a
lot of energy. Energy is require to operate processing plants, to transport crops to various
locations and to operate machines such as combine harvesters.
- The Combine Harvester is a machine a versatile machine designed to efficiently
harvest a variety of grain crops. The machine reaps, threshes, and cleans a cereal crop
in one operation. This machine uses fossil based sources such as oil/petroleum for
energy. An ultimate result of using fossil fuel based energy sources is that gases such
as carbon dioxide and nitrous oxide are released into the atmosphere. These gases will
accelerate the process of global warming/climate change as they trap heat coming
from the earth’s surface.
- After crops are harvested they need to be transported to markets or factory for
processing. The trucks, trains and other mode of transportation as aforementioned
uses fossil fuel as energy sources. The exhaust coming from trucks release gases such
as nitrous oxide, carbon dioxide into the atmosphere. The fumes/smokes can result in
air pollution.
 In some developing countries crops such as Sugar Cane are burnt prior to harvesting. The
fields are burnt to remove the unwanted leaves and dangerous insect/pests. The smoke

251. Oral Johnson
can result in air pollution (air quality is reduced) and surrounding communities are
affected.
Measures to ensure the sustainable management of resources- regional, personal and
national responses in primary, secondary industries and tourism
Farming
 Farmers can adopt organic farming practices. Organic farming is when farmers use
natural inputs rather than artificial inputs e.g. artificial fertilizers. Animal manure can be
used as a source of fertilizer. When natural inputs are used there is little or no impact of
the environment. Mulching is also practiced. This is when plant material twigs, grasses,
leaves straw are used to cover the top soil. It prevents weed from growing and keep the
soil moist by preventing evaporation. Government can educate farmers about the
benefits of organic farming so they can adopt this technique.
 Soil conservation technique such as terracing can be used on steep slopes. Terracing is a
where the natural landscape is transformed into stair steps of successively receding flat
surfaces. This reduces soil erosion.
 There are certain practices such as agroforestry and crop rotation that are also beneficial
to the environment. When a single crop is grown in one field for many years in a row, the
crop will cause the depletion of particular nutrients from the soil. This depletion of
nutrients leads to poor plant health and lower crop yield. With crop rotation, particular
nutrients are replenished depending on the crops that are planted. For example, a simple
rotation between a heavy nitrogen using plant (e.g., corn) and a nitrogen depositing plant
(e.g., soybeans) can help maintain a healthy balance of nutrients in the soil.
 Agro forestry includes the growing of tree crops with regular crops. Planting tree crops
can be advantageous. Firstly the tall trees encourage infiltration and reduces surface
runoff and can prevent soil erosion. The trees also acts as wind barriers and can protect
the plants at lower levels from wind erosion and damage by high speed winds.
 Contour cropping is a conservation farming method that is used on slopes to control
erosion. Contour cropping involves planting crops across the slope instead of up and

252. Oral Johnson
down the slope. Using contour cropping helps against erosion by keeping valuable topsoil
and by slowing down water so that it soaks in the ground.
 Fallowing ( or resting the land) should also be practice more by farmers. After a few
years of planting the soil is left to REST. Growing a crop continously on a piece of land
can decline soil quality overtime as specific nutrients are being used up. When the soil is
left to fallow (rest) for a few years the soil can regain its fertility naturally.
Fishing
 Fishermen are using destructive fishing practices which are affecting important
ecosystems such as coral reefs. Some fishermen will continue to use these practices.
Government can ban the use of these practices and improper fishing gears. In Barbados
cyanides and blast fishing are illegal.
 Government can implement closed seasons for certain species e.g. lobsters, parrot fish. In
the off season they can reproduce and continue to replenish stocks. In Barbados there are
closed seasons for the parrot fish. This prevents overfishing of important reef fisheries
that helps to protect the reefs.
 Government can enforced minimum sized weights for fish (in Belize conch shell must
exceed 7 inches). This enforcement allows only mature species to be removed from
marine areas. This will also prevent fishermen from catching young fishes and other
immature marine animals.
 Government should educate fishermen on the importance of the parrot fish to the
environment.
Tourism
 The tourism industry is degrading the environment. The Caribbean governments can
promote ecotourism. This form of tourism is environmentally friendly. The environment
is not affected and communities and local people benefit more from this type of tourism.
The Caribbean is endowed with natural scenery (mountains, caves etc.). This is a
sustainable type of tourism as money is still being generated, communities and local
benefits from it and it is environmentally friendly.

253. Oral Johnson
References
Bunnett, R. (1973). General Geography in Diagrams. Harlow, Essex: Pearson Education Limited.
Nelson Thrones. (2012). Csec Geography: for self study and distance learning . Delta Place,
Cheltenham.
Geo for CXC. (n.d.). Retrieved from https://www.geoforcxc.com/
Guinness, P., Rocke, J., Nagle, G., Oliphant, K., Rae, A., Ross, S., … Wyllie, A. (2008). Geography
for Csec. Nelson Thornes Ltd.
London, N., & Senior, M. (2004). Principles of Geography for Cxc (2nd ed.). Kingston: Carlong
Publishers Limited.
Seasley , N. (2010). Geography for Csec Examinations. Macmillan Education.
Waugh, D. (2002). Geography an Integrated Approach (3rd ). Delta Place, Cheltenham: Nelson
Thornes.
Wilson, M. (2005). The Caribbean Environment for Cxc Geography . Oxford, New York: Oxford
University Press.