"How inappropriate to call this planet Earth, when clearly it is Ocean." Arthur C. Clarke, author.

1. "How inappropriate to call this planet Earth, when clearly it is Ocean." Arthur C. Clarke, author.

6. Ground water • 100 x more groundwater than all water in rivers and lakes • Water that does not run off or evaporate seeps into ground • Some water clings to roots and soil • Continues downward movement through soil, sand, rock • http://www.kingcounty.gov/environment/waterandland/groundwater/education/animation.aspx

10. Groundwater Recharge When it rains, percolation into groundwater or runoff into streams, rivers, lakes

11. Groundwater Removal

12. Saltwater Intrusion

14. Decreasing groundwater supplies

15. http://ga.water.usgs.gov/edu/totrendbar.html

16. http://ga.water.usgs.gov/edu/totrendbar.html

17. Water Problems in US and Canada-Groundwater • Aquifer Depletion

18. Too Much Water • Flooding • Both natural and human-induced

19. Flooding

21. Floodplain • Natural feature of rivers • Mostly flat land adjacent to river. • Reduce severity of floods- • Absorb water • When built on, that area floods

22. Urban vs. Pre-Urban Floodplains

23. Urban StreamRural Stream Rural stream doesn’t increase in flow as much during heavy rains.

24. Floodplain • Government restrictions on building • Levees can fail • Rather than rebuild levees adjacent to rivers, experts suggest allowing some flooding of floodplains during floods

25. Left: Traditional levees adjacent to river Right: Suggested levee style, set back from river

26. Wetlands

27. Benefits of wetland areas • Heavy plant growth holds soil, prevents runoff • Allow water to seep into groundwater • Wetlands filter water • Phosphorus, metals get trapped in sediments • Neutralize harmful bacteria

28. Disappearing wetlands • In past 200 years, 20% of wetlands in US have been drained, filled, or otherwise degraded • In Philippines, 80% of coastal wetlands have been destroyed in last 30 years

29. Increases risk of flooding • Plants don’t hold water • Runoff increases • Erosion • Flooding • Reduced biodiversity

30. Deforestation- Pakistan Floods 2010 Pakistan has only 5.2 per cent forest cover, but had it had the necessary 20 to 25 per cent, the ferocity of the floods would have been minimized and the damage caused far milder. …..by trapping rain water in leaves, branches and roots, forests serve to slow down the flow of flood water. In contrast, deforested areas become more susceptible to flooding and landslides.

31. Not Enough Water- Droughts

33. How Humans Increase Drought An average temperature change of 5° F could change weather patterns.

34. more precipitation where it's already wet and less where it's already too dry • decrease in April 1st snowpack, a standard measurement used to project river basin runoff; • an 8 to 20 percent decrease in average annual stream flow in several river basins, including the Colorado, the Rio Grande, and the San Joaquin.

35. How Humans Increase Drought • Decreases in stream flow “will directly affect the West's water supplies, which are already stretched in meeting demands for drinking, irrigating crops, generating electricity and filling our lakes and aquifers for activities like fishing, boating and to power our economy," • Secretary of the Interior Ken Salazar

36. Droughts– Effect on soil • Nutrient cycling depends on water • Top layer of soil can blow away • Take nutrients away making land useless for agriculture for decades • Remaining soil hardens making it impermeable leading to erosion and flash flooding

37. Desalinization • http://www.youtube.com/watch?v=gA_XVxhBmTQ • http://www.youtube.com/watch?v=qZ5ut_4zKug