WATER USE & DISTRIBUTION

Environmental Science

Key HKey H220 Characteristics0 Characteristics

• Water is the prime constituent of all living organisms.

• Water moves easily-from one physical state to another, and from one place to another.

• Water slowly absorbs and releases large quantities of energy.

• Water is a superior solvent.

• Michael D. Lee Ph.D. Geography and Environmental Studies

(Source: Wright & Nebel 2002)

Available WaterAvailable Water

• Total = 326 million cubic miles • 97% of Earth’s water is in

oceans• 2.997% is locked up in ice

caps and glaciers• 0.003% is easily accessible

– Soil moisture– Groundwater– Water vapor– Lakes– Streams

http://ga.water.usgs.gov/edu/waterdistribution.html

Water Supply & UseWater Supply & Use

Use of Fresh WaterUse of Fresh WaterUnited States• 41% agriculture• 38% power plant cooling• 11% industry• 10% public

China• 87% agriculture• 7% industry• 6% public

Water UseWater Use Globally Globally People and Planet

• 70% of water for human use is soaked up by agriculture ( in the form of irrigation)

• Industry accounts for 23%

• Domestic use (household, drinking water, sanitation) accounts for about 7 %

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Irrigation

Industry

Domestic

Agriculture-70%Agriculture-70%

• Early forms of irrigation water never reaches crop. Much is lost to evaporation b/c they use flood or furrow irrigation.

• Sprinklers are more efficient & can be used on uneven land. Cost $ and still have problem with evaporation

• Best method- Drip irrigation- system of tubes deliver water directly to roots. Efficient but $$$

Industry- 23%Industry- 23%

• Cooling power plants• Generating electricity• Many industries

locate on rivers b/c– Used in manufacturing

process– Used for transportation

of goods

Domestic Use- 7%Domestic Use- 7%

• Cooking • Cleaning• Drinking• Bathing• Clothes washing• Flushing toilet• Washing Car

Water Use - Water Use - (minimum 13 gallons) (minimum 13 gallons) People and Planet

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UnitedStates

Netherlands

Gambia

average person in the U. S. uses between 65-80 gallons of water per day for drinking, cooking bathing, and watering their yard. average person in the Netherlands uses 27 gallons per day.average person in the African nation of Gambia uses 1.2 gallons per day.

Depleting GroundwaterDepleting Groundwater

• Major pumping from well causes ground water to be depleted.

• Saltwater intrusion= when salt water rises up and is pumped out of well.

DesalinationDesalination(removing salt from ocean water

• Heat salt water and collect fresh water that condenses.

• Used mostly in Middle East.

• Very expensive process because is uses too much energy.

Water Management Projects

• Methods to bring and store water to areas where there is not enough ground or surface water.

• Dams and reservoirs• Ex. Hoover dam,

Lake Lanier & Lake Allatoona

Large Dams Large Dams • PROS• Collect and store water

from rain and snow• Produce electricity• Irrigate land • Control flooding • Provide water to cities• Provide recreation such

as swimming, boating, fishing

• CONS• loss of water due to

evaporation• Flooded land destroys

forests or cropland and displaces people

• Danger of dam collapse• Migration and spawning

of fish disrupted• Causes water wars

between states• Expensive to build

Three Gorges DamThree Gorges Dam• World's largest hydroelectric dam, Three

Gorges, Yangtze River. • 1.2 - 1.9 million people will be displaced.• The entire project is to be completed in 2009.