Surface Water

The Water Cycle

http://observe.arc.nasa.gov/nasa/earth/hydrocycle/hydro3.html

Water Budget

•a continuous cycle of evaporation,

condensation, and precipitation

Earth’s Water Budget

• Earth’s water budget is balanced because the amount of precipitation = evaporation

precipitation= income evaporation and runoff= expenses

Local Water Budget • local water budgets are NOT balanced

due to: 1. temperature 2. vegetation 3. wind 4. amount and duration of rainfall

(E)

Precipitation (minus) Evaporation

WATER BUDGET DIAGRAM

Water Conservation • each person in the U.S. uses

~65,700 gallons of TREATED water each year (180 gal per day)

–Showers and baths, laundry, dishes, brushing teeth, drinks, watering lawns

Agriculture and industry use the greatest amount of water

two ways to insure that there is water for tomorrow:

• conserve, conserve, conserve!

• desalination (removing salt from the ocean water)

Desalination Plant in Key West, FL

How to conserve water at home:

http://www.epa.gov/epahome/athome.htm

90% of this used water is returned to rivers, lakes,

oceans, etc.

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