WATER USE & DISTRIBUTION Chapter 11 Environmental Science

Key H 2 0 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 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

Water Supply & Use

Use of Fresh Water United States 41% agriculture 38% power plant cooling 11% industry 10% public China 87% agriculture 7% industry 6% public

Water Use Globally People and Planet People and Planet 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 %

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% Cooling power plants Generating electricity Many industries locate on rivers b/c –Used in manufacturing process –Used for transportation of goods

Domestic Use- 7% Cooking Cleaning Drinking Bathing Clothes washing Flushing toilet Washing Car

Water Use - (minimum 13 gallons) People and Planet People and Planet People and Planet  average person in the U. S. uses between 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 Groundwater Major pumping from well causes ground water to be depleted. Saltwater intrusion= when salt water rises up and is pumped out of well.

Desalination Desalination (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 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 Dam World's largest hydroelectric dam, Three Gorges, Yangtze River million people will be displaced. The entire project is to be completed in 2009.