water use & distribution
TRANSCRIPT
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.