Earth's Waters

2. Hydrosphere
The part of the earth that includes the oceans, seas,
rivers, lakes and springs, as well as subsurface waters, ice caps
and glaciers.
Fresh Waters
Seawater
Groundwater
Surface Water
Ocean and Seas

3. Fresh Waters
Fresh waters
- about 97 percent of the earth’s water are stored in the earth’s oceans.
All other waters that is fit for human consumption and agriculture is called fresh
water.
The basic source of fresh water is precipitation, but not all precipitation
ends up as part of the freshwater supply.
Water moving across the surface is called runoff. Runoff begins as rain
accumulates in thin sheets of water that move across the surface of the land.
These sheets collect into a small body of running water is called stream.
A stream is defined as any body of water that is moving across the land.

4. Fresh waters
Runoff

5. Water that soaks into the ground moves down to a saturated zone where it
is called groundwater.
Groundwater moves through sediments and rocks beneath the surface,
slowly moving downhill.
An intermittent stream is one in which the source of groundwater is in low
supply and flow only part of the time.
The amount of rainfall that becomes runoff or groundwater depends on
the following factors:
1. The type of soil in the surface
2. how dry the soil is
3. the amount and type of vegetation
4. the slope of the land
5. if the rainfall is a long, gentle one or a cloudburst

6. Surface
WatersThe land area drained by a stream is known as the stream’s drainage
basin or watershed.
A line called divide separated two adjacent watersheds.
A continental divide separated river systems that drain into opposite
sides of a continent.
A smaller body of standing water is called a pond, and one of much
larger size is called a lake.
A natural pond or lake created by building dam is called a reservoir.

7. watershed
reservoirs
Taal lake

8. It is used for:
1. Water storage- A reservoir for water storage is kept as full as possible to store
water.
2. Flood control- A reservoir for flood control requires low water level in order to
catch runoff, preventing waters from flooding the land.
3. Generating electricity- A reservoir used to generate electricity requires the
release of water from the reservoir.
The water of streams, ponds, lakes and reservoirs are sources of fresh
water and is collectively called surface water.

9. Groundwate
rPrecipitation (rain or snow) that sinks into the ground forms the
groundwater reservoir.
The porosity of the soil or sediment.
Permeability of the soil.
The amount of precipitation, which makes its way into the ground,
depends on two factors:
The ability of a given sample of sediment to permit water to pass
through them is a measure of its permeability.
Porosity is the total amount of pore spaces in a
given sample of sediments.

10. The amount of groundwater available in a given place depends on:
present and past climate
slope of the land
Porosity and permeability of the
sediments beneath the surface.
Water from the zone of saturation is considered to be ground water.
The surface boundary between the zone of saturation and the zone
above is called the water table.
A hole that is dug or drilled through the earth to the water table is called a
well.
Whenever the water table reaches the surface of the ground, a body of
water collects. Thus are formed the springs, lakes and swamps.

11. Groundwater

12. well.
Spring Swamp
pond

13. The depth of the water table differs from place to place and depends upon several
factors:
1. • The thickness of the porous mantle
2. • the slope of the rock
3. • the amount of rainfall
4. • the vegetation cover.
An aquifer is a layer of sand, gravel, sandstone, or other highly permeable
material beneath the surface that is capable of producing water.
Groundwater that is under such a confining pressure is in an artesian
aquifer.
“Artesian” refers to the pressure and groundwater from an artesian well
rises above the top of the aquifer by not necessarily to the surface.

15. Fresh Water as Resource
Water is a very important resource because it is used
for many purposes – biological, domestic, agricultural, and
industrial purposes.
Surface water contains more sediment, bacteria and
possible pollutants than groundwater because it is more
active and is directly exposed to the atmosphere.
This means that surface water requires filtering to
remove suspended particles, treatment to kill bacteria and
sometimes processing to remove pollution.
As human population grows and new industries develop,
more and more demands are placed on the surface water supply,
which has already been committed to other uses, and on the
diminishing supply of groundwater.
Possible sources of fresh water that can answer problems
of water supply is the recycling of waste water and turning to the
largest supply of water in the world, the ocean.
About 90% of the water used by industries is presently
dumped as waste product.

16. Water Pollution
Any alteration in the original quality of the water brought about by the
introduction of organic substances or a change in the temperature or water is called
water pollution.
Pollutants
Sediments -Surface water
Wastes arising out of human activity (sewage waste, industrial effluents,
litter, animal manure, insecticides and mine tailing)
Inorganic water pollutants (mineral acids, inorganic salts and finely divided
metals or metal compounds)
mine drainage (sulfuric acid, soluble iron compounds)
organic water pollutants (oxygen-demanding compounds from: sewage,
both animal and domestic, industrial wastes from food processing plants
and effluents from slaughterhouses and meatpacking plants)
Synthetic organic compounds (detergents, household cleaning products,
new synthetic pesticides such as DDT, dieldrin and chordane, synthetic
industrial chemicals of a wide variety and waste from the manufacture of
these products)

17. mine drainage
Water
Pollution

18. Inorganic water pollutants

19. The most abundant element involved in this type of pollutant is carbon
which is easily broken down or decayed by bacteria in the presence of oxygen.
These pollutants increase the water’s acidity, salinity, toxicity or
radioactivity.
Increased acidity of water may lead to the destruction of aquatic life,
damage to agricultural crops, and excessive corrosion of plumbing systems, boats,
and related structures.
Sources of Salinity:
industrial effluents containing inorganic salts
water used as irrigation that dissolves large amounts of minerals from soil
salt brines released from mines or oil wells, and
tidal flow from the sea

20. Thermalwaterpollution originates with the practice of using water as coolant
in many industrial processes and returning it thermally enriched to the original
sources.
Heat is considered a water pollutant for the following reasons:
it reduces the solubility of oxygen in water
The higher water temperature may have a direct detrimental effect in fish and
aquatic life by changing their physical environment.
In organic salts such as phosphates and nitrates are plant nutrients and
their enrichment in water is known as eutrophication.