1. THE WATER FORMS
BY
JOVILYN MANALIGOD
CHRISTIAN RABAGO
BACHELOR OF ELEMENTARY EDUCATION
2. WATER FORMS ARE COMPOSE OF:
MARINE WATER
COASTAL AND OCEANIC WATER
SUBSURFACE WATER
WELLS, SPRINGS, HOT SPRINGS, GEYSERS AND
AQUIFERS
FRESH SURFACE WATER
RIVERS, STREAMS, LAKES, SWAMPS, GULFS,
BAYS, STRAITS, CANALS AND WATERFALLS
3. TERMINOLOGY:
HYDROLOGY – IS THE STUDY OF THE WATER OF
THE EARTH IN THEIR SEVERAL STATES ( SOLID,
LIQUID AND VAPOR ) AND THE DIVERSE PATHS THAT
LNK TOGETHER THE OCEANS, ATMOSPHERIC
MOISTURE AND SURFACE AND GROUNDWATER IN THE
CONTINENT.
THE HYDROSPHERE – THE TOTAL VOLUME OF
WATER AT OR NEAR THE EARTH’S SURFACE IS
APPROXIMATELY 1, 500, 000, 000 CUBIC KILOMETERS
( 350, 000, 000 CUBIC MILES ) OF WHICH ALMOST
99% IS CONTAINED IN THE DISCONTINOUS OCEANIC
WATER LAYER.
4. OCEANOLOGY - THE STUDY OF THE
OCEANS AND SEAS.
POTAMOLOGY - THE STUDY OF
RIVERS.
LIMNOLOGY - THE STUDY OF INLAND
WATERS SUCH AS LAKES AND PONDS,
RIVERS, STREAMS, SPRINGS, AND
WETLANDS.
6. OCEANS
An ocean is a body of saline water that
composes much of a planet's
hydrosphere. On Earth, an ocean is
one of the major conventional
divisions of the World Ocean, which
occupies two-thirds of the planet's
surface.
8. THE OCEAN OF THE WORLD
PACIFIC OCEAN
- THE LARGEST OF ALL THE OCEANS IS THE PACIFIC. IT INCLUDES
THREE-EIGHTS OF THE TOTAL AREA OF THE EARTH’S SURFACE. IT IS THE
DEEPEST OF THE OCEANS; IT HAS AN AVERAGE DEPTH OF ABOUT 14, 000
FEET. IT HAS AN AREA OF ROUGHLY 64, 000, 000 SQUARE MILES FILLS THE
MONSTROUS OVAL BETWEEN THE AMERICAN AND THE EASTERN COASTS
OF ASIA AND AUSTRALIA.
- PACIFIC OCEAN (Location) – THE PACIFIC OCEAN BOUNDS ASIA AND
AUSTRALIA TO THE WEST, THE AMERICAS TO THE EAST, THE ARCTIC TO
THE NORTH AND ANTARTICA TO THE SOUTH.
9.
10.
11. ATLANTIC OCEAN
- NEXT IN SIZE IS THE ATLANTIC, WHICH TAKES IN ONE-QUARTER OF THE AREA THE SEA. THE ATLANTIC
ALSO RANKS SECOND IN DEPTH, WITH AN AVERAGE OF ABOUT 13, 000 FEET. FILLING THE GAP
BETWEEN THE EAST COASTS OF THE AMERICA AND THE WESTERN COASTS OF EUROPE AND AFRICA IS
THE ATLANTIC OCEAN. IT HAS AN AREA OF ABOUT 31, 830, 000 SQUARE MILES.
12. INDIAN OCEAN
- THE INDIAN OCEAN IS THE THIRD IN SIZE WITH ABOUT ONE-EIGHT OF THE TOTAL AREA OF
THE EARTH’S SURFACE. IT IS BORDERED BY AFRICA AND ASIA. IT EXTENTDS ONLY A SHORT
DISTANCE ACROSS THE EQUATOR INTO THE NORTHERN HEMISPHERE. IT HAS A FEW ISLANDS
AND ADJACENT SEAS AND HAS AN AVERAGE DEPTH OF 3, 890 METERS AND HAS AN AREA OF
73, 556, 000 km². IT LIES BETWEEN AFRICA, ASIA, AND AUSTRALIA. IT IS NEARLY AS LARGE AS
THE ATLANTIC OCEAN.
- FIVE FAMOUS ISLAND IN INDIAN OCEANS ARE AS FOLLOW: Réunion, Zanzibar,
Mauritius, Seychelles, and Madagascar
13.
14. ARCTIC OCEAN
- AROUND THE NORTH POLE IS THE ARCTIC OCEAN, A SMALL OCEAN WITH ONLY ONE-THIRTIETH
OF THE EARTH’S SURFACE. IT IS ALMOST COMPLETELY COVERED WITH ICE TO A
DEPTH OF ABOUT 10 FEET. IT IS FOUND IN THE NORTH POLAR REGION. IT SEPERATES
THE EURO-ASIATIC AND THE AMERICAN SHORES AND OPENS SOUTHWARD THROUGH
NARROW CHANNELS TO BOTH THE ATLANTIC AND PACIFIC OCEANS. ITS AREA IS ABOUT 5,
440, 000 SQUARE MILES.
15. ANTARCTIC OCEAN
- The waters surrounding the North Pole between North America and Eurasia. The smallest
ocean in the world, it is covered by pack ice throughout the year. The ocean surrounding the North
Pole, north of the Arctic Circle. It has an Area of about 14 100 000 square km (5 440 000 square
miles) covered waters surrounding the North Pole; mostly covered with solid ice or with ice floes
and icebergs. depths of less than 6,650 feet (2,000 metres) below sea level.
16. THE PHILIPPINES HAS THE LONGEST DISCONTINUOOUS COASTLINE IN THE
WORLD WITH 34, 600 K. M., TWICE LONGER THAN THAT OF THE UNITED
STATES. THE SEACOASTS ARE INDENTED WITH BAYS, HARBORS, AND GULFS.
THERE ARE 61 NATURAL HARBORS, 31 OF THEM DEVELOPED AND USED
EXTENSIVELY, AND 20 LAND-LOCKED STRAITS.
THE FINEST HARBOR IN THE FAR EAST IS MANILA, WITH AN AREA OF 1, 970
KM. AND A COASTLINE OF 192 KM.
17. THE SEAS
THE PHILIPPINES HAS THE LONGEST DISCONTINUOOUS COASTLINE IN THE WORLD WITH 34, 600
K. M., TWICE LONGER THAN THAT OF THE UNITED STATES. THE SEACOASTS ARE INDENTED WITH
BAYS, HARBORS, AND GULFS. THERE ARE 61 NATURAL HARBORS, 31 OF THEM DEVELOPED AND
USED EXTENSIVELY, AND 20 LAND-LOCKED STRAITS.
THE FINEST HARBOR IN THE FAR EAST IS MANILA, WITH AN AREA OF 1, 970 KM. AND A COASTLINE
OF 192 KM.
18. THE WORLD'S SEAS INCLUDE:
ANDAMAN SEA - IS THE NORTHEASTERN ARM
OF INDIAN OCEAN, WITH AN AREA OF 308, 000
SQ. MILES (978, 000 SQ. KM. ). IT IS BOUNDED BY
THE IRRAWADY DELTA ( NORTH ), BY PENINSULAR
BURMA, THAILAND, AND MALAYSIA ( EAST ), BY
THE ANDAMAN AND AND NICOBAR ISLANDS ( WEST
), AND BY SUMATRA ( INDONESIA ), AND STRAIT
OF MALACCA ( SOUTH ). THE SEA IS 750 MILES (
1, 200 KM. ) LONG FROM NORTH TO SOUTH AND
400 MILES WIDE.
19.
20. BALTIC SEA - IS THE WORLD'S LARGEST
BODY OF BRACKISH WATER. IT HAS AN AREA OF
1, 600 SQ. MILES ( 42, 000 SQ. KM. ). IT CURVES
NORTHWARD FROM THE LATITUDE OF DENMARK
ALMOST TO THE ARCTIC CIRCLE, SEPERATING
THE SCANDINAVIAN PENINSULA FROM THE MAIN
BODY OF THE EUROPIAN LANDMASS.
21.
22. BARRENTS SEA- IS THE OUTLYING PORTION OF THE ARCTIC
OCEAN. IT IS 800 MILES ( 1, 300 KM ) LONG AND 650 MILES WIDE AND
HAS AN AREA OF 542, 000 SQ. MILES ( 1,405, 000 SQ. KM. ).
23. BERING SEA - IS THE BODY OF WATER IN THE NORTHERNMOST PACIFIC
OCEAN, SEPERATING THE CONTINENTS OF ASIA ( NORTHEASTERN SIBERIA ) AND
NORTH AMERICA ( ALASKA ). THE BERING SEA COVERS 890, 000 SQ. MILES 9 2,
304, 000 SQ. KM. ) AND CONNECTS WITH THE ARCTIC OCEAN BY WAY OF
BERING STRAIT, WHICH IS 53 MILES ( 85 KM. 0 WIDE AT ITS NARROWEST POINT.
24. CARRIBEAN SEA - IS A SUBOCEANIC BASIN, PART OF ATLANTIC OCEAN,
APPOX. 1, 020, 000 SQ. MILES ( 2, 640, 000 KM. ) IN EXTENT. TO THE SOUTH, IT IS
BOUNDED BY THE NORTHERN COAST OF SOUTH AMERICA, TO THE WEST BY THE
SOASTLINE OF CENTRAL AMERICA AND YUCATAN, TO THE NORTH BY THE GREATER
ANTILLES, AND TO THE EAST BY THE LESSER ANTILLES.
25. CHINA SEA - IS THE PART OF THE WESTERN PACIFIC OCEAN BORDERING ON
THE SOUTH ASIAN MAINLAND. IT COVERS AN AREA OF ABOUT 1, 340, 000 SQ.
MILES ( 3, 465, 000 SQ.KM. ) AND CONSIST OF THE SOUTH CHINA SEA AND EAST
CHINA SEA, WHICH CONNECT TO THE FORMOSA STRAIT BETWEEN TAIWAN AND
CHINA MAINLAND.
26. RED SEA - CONTAINS THE WORLD'S HOTTEST AND SALTIEST SEA WATER. A
NARROW STRIP OF WATER EXTENDING SOUTHEASTWARD FOR 1, 300 MILES ( 2,
100 KM. 0, FROM SUEZ TO THE BAB (STRAIT) EL- MANDEB AND THE GULF OF
ODEN. IT SEPERATES NORTHEAST AFRICA FROM THE ARABIAN PENINSULA. IT HAS
AN AREA OF 169, 000 SQ. MILES ( 438, 000 ) SQ. KM. ) WITH DISTANCES VARYING
FROM 130 TO 250 MILES ( 210-400 KM. ).
27. SEA OF JAPAN - IS THE MARGINAL SEA OF THE PACIFIC OCEAN WHICH
LIES BETWEEN JAPAN AND THE SOVIET ISLAND OF SAKHALIN (EAST) AND
THE ASIAN MAINLAND OF THE SOVIET UNION AND KOREA (WEST). IT HAS
SURFACE AREA OF 389, 100 SQ. MILES ( 1, 007, 800 SQ. KM. ) AND A MEAN
DEPTH OF 4, 429 FT. ( 1, 350 M. ).
28. PHILIPPINE SEA -The Philippine Sea is bordered by the Philippines and
Taiwan to the west, Japan to the north, the Marianas to the east and Palau to the
south. Adjacent seas include Celebes Seawhich is separated by Mindanao and
smaller islands to the south, South China Sea which is separated by Philippines,
and East China Sea which is separated by the Ryukyu Islands.
They surround an area measuring 1,800 miles (2,900 km) north-south by
1,500 miles east-west and occupying a total surface area of 40,000 square
miles (1,000,000 square km), about 3 percent of the entire Pacific region.
The basin, with a general depth of 19,700 feet (6,000 m), plunges to its
greatest depths in trenches to the east of the island arcs. The deepest is
the Philippine Trench at 34,578 feet (10,539 m).
29.
30. MEDITERRANEAN SEA - IS AN INTERCONTINENTAL
BODY OF WATER LYING BETWEEN SOUTHERN EUROPE ( TO
THE NORTH ), NORTH AFRICA ( TO THE SOUTH ), AND THE
SOUTHWESTERN ASIA ( TO THE EAST ). IT IS LINKED TO
THE ATLANTIC OCEAN BY THE NARROW STRAIT OF
GIBRALTAR IN THE WEST AND CONNECTS WITH THE BLACK
SEA IN THE NORTHEAST VIA THE SEA OF MARMARA. IT IS
ABOUT 2, 500 MILES LONG AND HAS A MAXIMUM WIDTH OF
850 MILES AND A TOTAL AREA ( EXCLUDING THE SEA OF
MARMARA AND THE BLACK SEA ) OF 970, 000 SQ. MILES.
31.
32. BLACK SEA - The Black Sea lies between
southeastern Europe and Asia Minor. Excluding its
northern arm, the Sea of Azov, the Black Sea
occupies about 168,500 square miles (436,400
square kilometers). It is connected to the Aegean Sea
through the Bosporus, the Sea of Marmara, and the
Dardanelles, and has been of critical importance to
regional commerce throughout the ages.
33.
34. SEA WATER COMPOSITION
GEOLOGISTS BELIEVE THAT THE EARTH IN ITS EARLY STAGES WAS WITHOUT
OCEANS. ALL THE EARTH'S WATER WAS PROBABLY CHEMICALLY BOUND WITHIN
THE ROCKS UNTIL VOLCANISM RELEASED IT. SOME OF TH VOLCANIC ACTIONS
ORIGINALLY PRODUCE THE OCEANS ARE STILL GOING ON. THUS, IT IS
REASONABLE TO SUPPOSE THAT THE OCEANS ARE STILL GROWING TODAY.
THE COMPOSITION OF SEA WATER TODAY IS NOT THE SAME AS THAT OF THE
WATER THAT FILLED THE ORIGINAL OCEANS. WHEN THE WATER WAS FIRST
RELEASED FROM THE ORIGINAL ROCKS, IT WAS NOT SALTY. IT ONLY BECAME
SALTY AFTER RAIN HAD WASH OVER THE LAND ON ITS WAY TO THE OCEANS
BASINS. AS THE LAND WAS FLOODED BY THE DOWNFALL OF RAIN, MINERALS
WERE DISSOLVED AND CARRIED INTO THE SEA. SINCE THE OCEANS WERE
FORMED, THE SAME PROCESSED HAVE BEEN GOING ON AGAIN AND AGAIN IN AN
ENDLESS HYDROLOGIC CYCLE.
THE MOST ABUNDANT AND SOLUBLE IN WATER AND COMMON MINERAL IS THE
TABLE SALT ( SODIUM CHLORIDE ) LEADS THE FIRST.
35. MINERALS FROM THE SEA
THE DISSOLVED MINERALS IN THE SEA WATER ARE USEFUL AND
VALUEABLE.
EACH CUBIC MILE OF SEA WATER CONTAINS ABOUT 4 MILLION TONS OF
MAGNESIUM. THESE LIGHT METALS ARE USED IN AIRCRAFT AND MANY
OTHER APPLICATIONS.
ALMOST ALL OF THE WORLD'S SUPPLY OF MAGNESIUM IS EXTRACTED
FROM SEA WATER. THE ELEMENT BROMINE ( USED IN HIGH TEST
GASOLINE AND PHOTOGRAPHIC FILM ) AND MANY CHEMICALS ARE
OBTAINED FROM SEA WATER.
NATURALLY, THE SEA IS AN IMPORTANT SOURCE OF ORDINARY SALT. THIS
IS AN ESSENTIAL MATERIAL FOR SEVERAL CHEMICAL INDUSTRIES. ***
36. ECONOMIC ASPECTS OF OCEANS AND SEAS
THE SEA IS GENERALLY ACCEPTED BY SCIENTISTS AS THE PLACE
WHERE LIFE BEGAN ON EARTH. WITHOUT THE SEA, LIFE AS IT IS
KNOWN TODAY WOULD NOT EXIST. IT ACTS AS A GREAT HEAT
RESERVOIR, LEVELLING THE TEMPERATURE EXTREMES THAT
WOULD OTHERWISE PREVAIL OVER THE EARTH AND EXPAND THE
DESERT AREAS.
THE OCEANS PROVIDE THE LEAST EXPENSIVE FORM OF
TRANSPORTATION KNOWN TO MAN, AND THE MARGINS OF THE
SEA SERVE AS ONE OF THE MAJOR SITES OF RECREATION.
THE SEA IS A MAJOR SOURCE OF FOOD AND A DUMPING GROUND
FOR MANY WASTES. THE SEA IS ALSO A MAJOR POTENTIAL
SOURCE OF PROTEIN, MINERALS, AND POWER, ALL OF WHICH
ARE REQUIRED IN EVER-INCREASING QUANTITIES BY ALL
INDUSTRIAL SOCIETIES.
37. THE SEA IS ALSO USED AS A SOURCE OF :
FOOD AND WATER
FISHING --- MAN CAN GET 60, 000, 000 TONS OF FOOD FROM THE OCEAN ANUALLY BY
FISHING.
ENERGY RESOURCES
A. POWER GENERATION--- ENERGY IS EXTRACTED FROM THE TIDES OF THE
OCEAN.
B. MINERALS--- BILLIONS OF TONS OF MINERAL CAN BE OBTAINED FROM THE SEA.
C. PETROLEUM--- 2, 000, 000, 000, 000 BARRELS OF OIL RESOURCES CAN BE OBTAINED.
BUILDING PRODUCTS
SAND, GRAVEL, AND LIME.
JEWELRY
CORALS AND PEARLS
FERTILIZERS
SEAWEEDS AND DEAD ORGANISM
40. GROUND WATER - IS FOUND AT MOST A FEW
KILOMETERS FROM THE CRUST.
SUBSURFACE WATER - THESE ARE WATER
THAT OCCUPY PORES SPACES BELOW THE GROUND
SURFACE.
41. WELLS - IS A HOLE THAT IS DUG OR DRILLED DEEP ENOUGH INTO THE
GROUND TO REACH THE WATER TABLE. IT IS FORMED WHEN WATER FLOWS
INTO AND FILLS UP THE HOLE. WELLS IN PERMEABLE SEDIMENTARY ROCKS
WHERE THE GRADIENT OF WATER IS GOOD WILL USUALLY PROVIDE AN
ABUNDANT SUPPLY OF WATER. THE WATER WITHDRAWN IS QUICKLY
REPLENISHED BY THE RAPIDLY MOVING GROUND WATER. HOWEVER, IF THE
WELL IS TOO SHALLOW, THE WATER TABLE MAY DROP BELOW THE WELL IN
DRY PERIODS.
ARTESIAN WELL - IS THE TYPE OF WELL WHEREIN THE WATER IS
OBTAINED FROM AN AQUIFER IN A POROUS ROCK LAYER USUALLY
CONSISTING OF SANDSTONE OR LOOSE SAND AND GRAVEL.
- IT IS USUALLY DRILLED SEVERAL THOUSAND FEET DEEP IN
ORDER TO REACHED THE AQUIFER. HOWEVER, ORDINARY WELLS ARE
FREQUENTLY SUNK THIS DEEP IN ORDER TO MAINTAIN CONSTANT
CONTACT WITH THE WATER TABLE.****
42.
43. AQUIFERS - An aquifer is an underground layer of water-bearing rock. Water-bearing
rocks are permeable, meaning that they have openings that liquids and
gases can pass through.Sedimentary rock such as sandstone, as well as sand and
gravel, are examples of water-bearing rock. The top of the water level in an aquifer is
called the water table.
- An aquifer fills with water from rain or melted snow that drains into the
ground.
- Aquifers act as reservoirs for groundwater. Wells drilled into aquifers provide
water for drinking, agriculture, and industrialuses.
- There are two types of aquifers. An unconfined aquifer is covered by
permeable rock and can receive water from the surface. The water table of
an unconfined aquifer rises or falls depending on the amount of water
entering and leaving the aquifer. It is only partly filled with water.
In contrast, a confined aquifer lies between two layers of less permeable
rocks and is filled with water. Water trickles down through cracks in the upper
layer of less permeable rock, a nearby water source, such as an underground
river or lake, or a nearby unconfined aquifer.
44.
45. SPRINGS-OCCURS WHENEVER GROUND WATER
COMES NATURALLY TO THE SURFACE. SOME
SPRINGS ARE DISCHARGED WHERE THE WATER
TABLE INTERSECTS THE LAND SURFACE BUT THEY
MAY OCCUR WHERE WATER FLOWS OUT FROM A
CAVERN OR ALONG FRACTURES, FAULTS, OR ROCK
CONTACTS THAT COME TO THE SURFACE.
- MAY OCCUR ON HILLSIDE WHERE THE WATER
TABLE INTERSECTS THE LAND SURFACE.
- SPRING WATER CONTAINING DISSOLVED
MINERALS COMES FROM WHAT ARE CALLED
MINERAL SPRINGS.***
46.
47. HOT SPRINGS - ARE FORMED WHEN WATER
GETS HEATED BY NEARBY MAGMA BEFORE COMING OUT
OF THE EARTH.
- WATER MAY ALSO BE HEATED BY MIXING
WITH STEAM AND HOT GASSES FROM BODIES OF MAGMA
ESCAPING INTO THE SURFACE.
- AROUND MOUNT MAKILING IN CALAMBA
AND LOS BANOS AND MAYON VOLCANO IN ALBAY ARE
PLENTY OF HOT SPRINGS.
- THE TEMPERATURE OF THE VARIOUS HOT
SPRINGS RANGES FROM 6 DEGREE TO 9 DEGREE
CELCIUS.***
48.
49.
50. GEYSERS - A HOT SPRING THAT EMITS STEAM AND HOT
WATER PERIODICALLY IS CALLED GEYSER. THE INTERVAL
BETWEEN ERUPTIONS INDICATES THE TIMES IT TAKES THE
GROUND WATER TO GET HEATED. A COLUMN OF STEAM AND
BOILING WATER MAY BE THROWN UP HIGH. THEN THE GROUND
WATER COLLECTS AGAIN AND THE PROSSESES ARE REPEATED.
SOME GEYSERS ARE LOCATED NEAR ACTIVE VOLCANIC AREAS AND
ERUPT FROM OPEN POOLS; OTHERS ERUPT THROUGH A SMALL
OPENING AND JETS OF WATER AND STEAM RESULT.
51.
52. SURFACE WATER
(LAKES, SWAMPS, RIVERS, STREAMS, STRAITS, GULFS, BAYS, CANALS AND
WATERFALLS)
53. LAKES - LAKES ARE COMMON ELEMENTS OF THE ANDSCAPE
FORMED WHEN A DEPRESSION CALLED A BASIN IS FILLED WITH
WATER.
- THEY ALSO SERVE AS RESERVOIRS, PROVIDING WATER
FOR GENERATING ELECTRICITY AND WATER USED IN INDUSTRY AND
AGRICULTURE.ALSO PROVIDE CHEAP TRANSPORTATION.
- FISHING IN THE LAKE IS A SOURCE OF LIVELIHOOD AND
A FORM OF RECREATION.
- THERE ARE ABOUT 59 LAKES IN THE COUNTRY. THE SIX
LARGEST LAKES ARE: LAGUNA DE BAY WITH AN AREA OF 922, 142
SQ. KM.; LAKE LANAO DEL SUR WITH AN AREA OF 374, 000 SQ. KM;
LAKE MAINIT IN SURIGAO DEL NORTE WITH AN AREA OF 150, 220
SQ. KM.; LAKE NAUJAN IN ORIENTAL MINDORO WITH AN AREA OF
69, 930 SQ. KM.; AND LAKE BULUAN IN SULTAN KUDARAT WITH AN
AREA OF 59, 570 SQ. KM.
- TAAL LAKE IN BATANGAS IS KNOWN AS THE SMALLEST
LAKE IN THE WORLD WITH AN AREA OF 234.2 SQ.KM.***
54.
55.
56.
57.
58.
59.
60. SWAMPS - BASIN THAT BECOME PARTLY OR
COMPLETELY FILLED WITH FRESH AND DECAYED
VEGETATION SEDIMENT IN WATER ARE CALLED
SWAMPS. THEY USUALLY ARE A STAGE IN THE
CHANGINGOF A LAKE OR POND INTO DRY LAND. THEY
BECOME LAKE DURING RAINY SEASONS AND SWAMPS
DURING DRY MONTHS. ***
61.
62. RIVERS - A river is a natural watercourse, usually freshwater,
flowing towards an ocean, a lake, a sea, or another river. In some
rare cases a river could flow into the ground and dry up completely
at the end of its course, without reaching another body of water.
Small rivers may be called by several other names, including
stream, creek, brook, rivulet, and rill.
STREAMS - MUCH RAIN IS ABSORB BY PLANTS AND SOIL. BUT
EXCESS RAIN RUNS OFF INTO LOW-LYING AREAS TO JOIN OR TO FORM
A STREAM.THEY ARE ALSO KEPT SUPPLIED BY WATER THAT
GRADUALLY SEEPS TOWARD THEM UNDER THE SURFACE OF THE
GROUND. A STREAM IS A FLOWING BODY OF WATER OR A SMALL
RIVER.
66. THERE ARE ABOUT 132 NAVIGABLE RIVERS AND VALUABLE MEANS OF
TRANSPORTATION IN THE COUNTRY.
THE CAGAYAN RIVER A.K.A. RIO GRANDE DE CAGAYAN IS THE LARGEST
WITH AN AREA OF 505 KM.
Economic importance of the C.R. The river drains a fertile valley that
produces a variety of crops, including rice, corn, bananas, coconut,
citrus and tobacco.
There are dams in two of the river's tributaries, the Magat and Chico
Rivers, and there are also several mining concessions in the mineral-rich
Cordillera Mountains near the headwaters of the two tributary rivers.
The provincial governments along the river have also developed tourism
programs that offer activities on the river, particularly whitewater
rafting.
OTHER IMPORTANT RIVERS IN LUZON ARE THE PAMPANGA AND AGNO
RIVER; AGUSAN AND PULANGI IN MINDANAO. THE PASIG RIVER IS THE
OUTLET OF LAGUNA DE BAY AND SITUATED AT ITS MOUTH IS THE CITY OF
MANILA.
69. CLASSIFICATION OF RIVER ACCRDNG TO THEIR
AGE
Youthful river: A river with a steep gradient that has very few tributaries and flows
quickly. Its channels erode deeper rather than wider. Examples include the Brazos, Trinity and
Ebro rivers.
Mature river: A river with a gradient that is less steep than those of youthful rivers and
flows more slowly. A mature river is fed by many tributaries and has more discharge than a
youthful river. Its channels erode wider rather than deeper. Examples include theMississippi,
Saint Lawrence, Danube, Ohio, Thames and Paraná rivers.
Old river: A river with a low gradient and low erosive energy. Old rivers are characterized by
flood plains. Examples include the Yellow,Ganges, Tigris, Euphrates, Indus and Nile rivers.
Rejuvenated river: A river with a gradient that is raised by tectonic uplift.
70. STRAIT - A strait is a naturally formed, narrow, typically navigable waterway
that connects two larger bodies of water. It most commonly refers to a channel
of water that lies between two land masses, but it may also refer to a
navigable channel through a body of water that is otherwise not navigable, for
example because it is too shallow, or because it contains an unnavigable reef or
archipelago.
GULF - a large bay that is an arm of an ocean or sea.
BAYS -A bay is a large body of water connected to an
ocean or sea, formed by an inlet of water due to the
surrounding land blocking some waves and often
reducing winds. Bays also exist in in-land environments
as an inlet to any larger body of water, such as a lake or
pond, or the estuary of a river, A large bay may be called
a gulf, a sea, a sound, or a bight. A cove is a circular or
oval coastal inlet with a narrow entrance; some coves
may be referred to as bays. A fjord is a particularly
steep bay shaped by glacial activity.
76. CANALS - Canals and navigations are human-made channels for
water. In the vernacular both are referred to as 'canals'. The main
difference between them is that a navigation parallels a river and
shares its drainage basin, while a canal cuts across a drainage
divide.
TYPES OF CANALS
There are two broad types of canal:
Waterways: canals and navigations used for carrying vessels transporting goods and people. These can be
subdivided into two kinds:
Those connecting existing lakes, rivers, other canals or seas and oceans.
Those connected in a city network: such as the Canal Grande and others of Venice Italy; the gracht of Amsterdam,
and the waterways of Bangkok.
Aqueducts: water supply canals that are used for the conveyance and delivery ofpotable water for human
consumption, municipal uses, hydro power canals andagriculture irrigation.
77. CONSTRUCTION OF CANALS:
A. HUMAN MADE STREAMS
B. CANALIZATION AND NAVIGATIONS
C. LATERAL CANALS
81. WATERFALLS - A WATERFALL IS ANY STREAM OF WATER DESCENDING
SUDDENLY FROM A HIGHER TO A LOWER LEVEL.IF THE VOLUME OF
WATER IS SMALL, IT IS CALLED A CASCADE;IF IT IS LARGE, IT IS CALLED A
CATARACT.
82. SUBSIDENCE
Subsidence is the motion of a surface (usually, the Earth's surface)
as it shifts downward relative to a datum such as sea-level.
Subsidence frequently causes major problems in karst terrains, where
dissolution of limestone by fluid flow in the subsurface causes the
creation of voids (i.e. caves). If the roof of these voids becomes too
weak, it can collapse and the overlying rock and earth will fall into
the space, causing subsidence at the surface. This type of subsidence
can result in sinkholes which can be many hundreds of meters deep.
Sinkhole is a depression or hole in the ground caused by some form
of collapse of the surface layer. Some are caused by karst processes
83. TYPES OF SINKHOLE
Solution Sinkholes
Solution sinkholes occur in areas where limestone is exposed at land
surface or is covered by thin layers of soil and permeable sand. Solution is
most active at the limestone surface and along joints, fractures or other
openings in the rock that permit water to move easily into the subsurface.
Dissolved limestone and some insoluble residue are carried downward by
percolating water along enlarged openings as solution of the limestone
progresses. Large voids commonly do not form because subsidence of the
soil layer occurs as the limestone surface dissolves. The result is a gradual
downward movement of the land surface and development of a depression
that collects increasing amounts of surface runoff as its perimeter expands.
This type of sinkhole usually forms as a bowl-shaped
The gently rolling hills and shallow depressions typical of solution-subsidence
topography are common over large parts of Florida.
84.
85. Cover Collapse Sinkholes
Cover-collapse sinkholes occur where a solution cavity develops in the
limestone to a size such that the overlying cover material can no longer
support its own weight. Collapse is generally abrupt when this occurs
and is sometimes catastrophic. Collapse sinkholes provide dramatic
local changes in topography. They may occur in any areas of soluble
rock; however, they are less likely to occur in areas of deeply buried
rocks.
Collapse sinkholes generally occur in areas where the limestone is near
land surface and the limestone aquifer is under water-table conditions.
Ground-water circulation is most vigorous at and just below the water-table
where solution of the limestone is accelerated. Accelerated
solution also may occur at certain depths where bedding planes in the
limestone or changes in rock composition concentrate the flow of
groundwater.
86.
87. Cover Subsidence Sinkholes
Cover-subsidence sinkholes occur where the cover material is
relatively incohesive and permeable, and individual grains of
sand move downward in sequence to replace grains that have
themselves moved downward to occupy space formerly held by
dissolved limestone. In areas where the sand cover is 50 to 100
feet thick, subsidence sinkholes generally are only are few feet
in diameter and depth.