2. LAKES
A LAKE IS AN AREA FILLED WITH WATER, LOCALIZED
IN A BASIN, SURROUNDED BY LAND, AND SET
APART FROM ANY RIVER OR OTHER OUTLET THAT
SERVES TO FEED OR DRAIN THE LAKE.
LAKES LIE ON LAND AND ARE NOT PART OF THE
OCEAN, ALTHOUGH, LIKE THE MUCH LARGER OCEANS,
THEY DO FORM
PART OF THE EARTH'S WATER CYCLE. LAKES ARE
DISTINCT FROM LAGOONS, WHICH ARE
GENERALLY COASTAL PARTS OF THE OCEAN.
LAKES ARE TYPICALLY LARGER AND DEEPER
THAN PONDS, WHICH ALSO LIE ON LAND,
THOUGH THERE ARE NO OFFICIAL OR SCIENTIFIC
DEFINITIONS
4. 10 COUNTRIES WITH THE MOST LAKES
1. CANADA – 879,800=Lake Superior
2. RUSSIA – 201,200=Lake Baikal
3. USA – 102,500= LAKE POWELL
4. CHINA – 23,800=TIANCHI LAKE
OR HEAVEN LAKE
5. • 5. SWEDEN – 22,600= Lake
Torneträsk
• 6. BRAZIL – 20,900=Lagoa da
Conceição
• 7. NORWAY – 20,000=Lake
Ringedalsvatnet
• 8. ARGENTINA – 13,600=Nahuel
Huapi Lake
6. • 9. KAZAKHSTAN – 12,400=Kolsay Lake
• 10. AUSTRALIA – 11,400=Lake Eyre
7. 10 MAJOR LAKE TYPES ARE:
• 1. TECTONIC LAKES- Tectonic lakes are
lakes formed by the deformation and resulting
lateral and vertical movements of the Earth's
crust.
2. VOLCANIC LAKES- A volcanic lake is a
cap of meteoric water over the vent of an active
volcano.
• 3. GLACIAL LAKES- Glacial lakes are
lakes created by the direct action of
glaciers and continental ice sheets.
• 4. FLUVIAL LAKES- Fluvial or
riverine lakes are lakes produced by
running water.
8. • 5. SOLUTION LAKES- A solution lake is a lake 7. AEOLIAN LAKES-
occupying a basin formed by surface
dissolution of bedrock.
• 6. LANDSLIDE LAKES- A landslide lake is created by
• the blockage
of a river valley by either mudflows, rockslides, or screes.
A lake that is often formed by
wind-blown sand deposits and
sand dunes.
8. SHORELINE LAKES- are generally lakes
created by blockage of estuaries or by the
uneven accretion of beach ridges by
longshore and other currents.
9. • 9. ORGANIC LAKES- Organic lakes are
lakes created by the actions of plants and
animals or actions of flora and fauna.
• 10. ANTHROPOGENIC LAKES-
Anthropogenic lakes are artificially created
as a result of human activity.
10. RIVERS
•A river is a stream of water that flows through
a channel in the surface of the ground. The
passage where the river flows is called the river
bed and the earth on each side is called a river
bank.
11. TYPES OF RIVER
1. Ephemeral Rivers
Dried up ephemeral river on a desert.
Whenever snow melts quickly or there is
an exceptionally heavy downpour,
it can result in an ephemeral river.
2. Episodic Rivers
Aerial view of an episodic river.
Although they are rare, episodic rivers
are formed from run-off channels
and found in areas with very dry climates.
12. 3. Exotic Rivers
Bridge over the Euphrates river.
Any river that flows through a
very dry region is called an exotic river.
4. Intermittent Rivers
Intermittent river beside the green banks.
These are rivers that have a semi-permanent
nature and are known because of their
seasonal flow.
13. 5. Mature River
A mature river is not very steep
and has a slow flow when compared
to youthful rivers.
6. Old Rivers
Old rivers have a low gradient
and they depend on floodplains.
14. 7. Periodic River
Periodic rivers have dry spells
throughout the year, especially if they
are located in very dry climates where
the precipitation is less frequent than
the amount of evaporation.
8. Permanent River
Permanent rivers are those
which have water all year around.
15. 9. Youthful River
With a steep gradient and only
a few tributaries, youthful rivers
flow swiftly and quickly.
16. HOW RIVERS ARE CLASSIFIED
1.Biotic Classification- Biotic classification refers to each
river’s ecosystem type, and it includes everything from
the purest and cleanest rivers to the most contaminated
ones.
It has a three different zone:
•Crenon zone
•Rhithron zone
•Potamon zone
17. 2. CHRONOLOGICAL CLASSIFICATION
• Chronological Classification go by the river’s age, which experts
can
study by researching its patterns of erosion.
They can be classified further into these three types of rivers:
•Mature river
•Old river
•Rejuvenated river
•Young river
18. 3. Strahler Stream Order
• This classification was developed in 1952 and is based on a
number called the Strahler number that shows how difficult it
is to branch numbers.
4. Topographic Classification
•Topographic classification involves the shape, physical
makeup, and specific features of the river.
There are three separate categories:
•Alluvial rivers
•Bedrock rivers
19. • 4. Whitewater Classification
• Rivers contribute to healthy ecosystems and provide fresh water,
but they can also be important aspects of a recreational activity.
• International Scale of River Difficulty has determined six different
whitewater classifications:
• •Class I
• •Class II
• •Class III
• •Class IV
• •Class V
• •ClassVI
20. ESTUARIES
• An estuaries is a partially enclosed coastal body of brackish water
with one or more rivers or streams flowing into it, and with a free
connection to the open sea. The tidal mouth of a large river, where
the tide meets the stream.
• Estuaries and their surrounding wetlands are bodies of water
usually found where rivers meet the sea. Estuaries are home to
unique plant and animal communities that have adapted to
brackish water a mixture of fresh water draining from the land and
salty seawater.
21. CLASSIFICATION OF ESTUARIES
• Estuaries can be classified into 4 types depending on their origins:
1. Coastal Plains/Drowned River Mouth:
In the past 18,000 years sea levels have risen some
125m.
2. Fjords:
Fjords are steep, caused by glacial eroding.
They are U-shaped.
22. 3. Bar-Built:
• Bar-built estuaries form when a barrier is built
parallel to the coast above sea level.
4. Tectonic:
Tectonic estuaries are coastal indentations due to faulting
and subsidence.
23. 5 IMPORTANCE OF ESTUARIES
1. Protecting lands from crashing waves and storms.
2. They help prevent soil erosion.
3. They soak up excess flood water and tidal surges.
4. They are important feeding and/or nursery habitat for commercially and
ecologically.
5. Important fish and invertebrates, and migrating birds.
24. THE 5 MAJOR TYPES OF ESTUARIES CLASSIFIED
ACCORDING TO THEIR WATER CIRCULATION
INCLUDE:
• 1. Salt-Wedge Estuaries-Salt-
wedge estuaries are the most
stratified or least mixed of all
estuaries. They are also called
highly stratified estuaries.
2. Fjord-type Estuaries- are typically
long, narrow valleys with steep sides that
were created by advancing glaciers.
25. 3. Slightly Stratified Estuaries-
In slightly stratified or partially
mixed estuaries, saltwater and
freshwater mix at all depths;
however, the lower layers of
water typically remain saltier
than the upper layers.
4. Vertically Mixed Estuary-A
vertically-mixed or well-mixed estuary
occurs when river flow is low and
tidally generated currents are
moderate-to-strong.
26. 5. Freshwater Estuaries-
Freshwater estuaries are semi-
enclosed areas of the Great
Lakes in which the waters
become mixed with waters
from rivers or streams.
