1. 15 - 1
The Water Cycle

2. Where did all the water come from?
Early Greeks thought it was supplied by rain and snow
Earth’s surface receives 5 times as much water as rivers can carry off
Where does it come from?
Where does it all go?

3. Movement of Water Two/thirds or 70 % of earth is covered in water
Lakes
Streams
Oceans
Ice
Groundwater

4. Water
Water is found in living tissues

5. Water Vapor and Clouds
Small invisible particles
Clouds and Fog

8. The Water Cycle
Constant movement of water between land, air, and water

9. Evaporation Liquid changes to a gas Every year:
500,000 km3 into oceans
86% from the ocean

10. Transpiration
Process in which plants and animals release water vapor into the atmosphere

11. Evapotranspiration Total water loss from an area: Evaporation

12. Condensation Water changes from a gas to a liquid
When water vapor become cooler it condenses

13. Precipitation Any water that falls to the Earth Rain Sleet Snow Hail
75% falls in the oceans

15. Water Budget Think of your own budget? Precipitation – income
Evapotranspiration and runoff - expenses

16. Determining Factors
Temperature
Vegetation
Wind
Precipitation duration

18. Drought
Evapotranspiration > precipitation

19. Flood
Evapotranspiration < precipitation

20. Water Use Each person, every year: 20,890.5 gallons
90% of water used by cities and industry is returned as wastewater

22. Conservation of Water Conserve water
Desalination – removing salt from ocean water
Expensive