1. Water §Importance and unique properties

2. Features §covers 71% of the Earth’s surface §regulates Earth’s climate §dilutes wastes §sculpts earth’s surface, §major habitat

3. Supply §97% in oceans §3% fresh water §2.997% in ice caps glaciers §.003% available to us

4. Watersheds - drainage basins §areas of land that drain into bodies of surface water §water flowing off land into these bodies is called surface runoff

5. Hydrologic Cycle §natural recycling and purification process §plenty of fresh water, if not overloaded with degradable and non-degradable material §divide world into “haves” and “have nots”

6. Solar powered hydrologic cycle §Evaporation §transpiration §condensation §precipitation §runoff §percolation §groundwater §water table

7. Surface water §precipitation that does not soak into the ground or return to the atmosphere by evaporation §streams, lakes, wetlands, reservoirs

8. Groundwater §precipitation infiltrates the ground and fills pores in soil and rocks §zone of saturation - all available soil and rock spaces filled by groundwater

9. Water Table §upper surface of zone of saturation poorly demarcated between saturated soil and rock and unsaturated soil and rock §falls in dry weather and rises in wet weather

10. Diagram- aquifer §Major reservoirs of groundwater §consolidated forms §solid rock with groundwater in cracks §unconsolidated forms §sand,gravel,loose earth §amount of water depends on packing

11. Cone of depression §withdrawal rate of aquifer exceed natural recharge rate

12. Use of water §mostly to irrigate crops(69%) §energy production- 23% §industrial usage highest in Europe and N.America (US)

13. Cause …freshwater shortages §???

14. Drought §at 40% of world population experience year long droughts §since 1970’s - more than 24,000 dead

15. Water - political issue

16. Water Resources in US

17. How do we increase water supply? §build dams and reservoirs §withdraw groundwater §increase water efficiency

18. Desalination §removal of dissolved salts from ocean or brackish water §7500 plants in 120 countries- 0.1% fresh water §distillation = heating salt water until it evaporates,salt left as solid §reverse osmosis - salt water pumped through thin membrane,salt left behind

19. Disadvantages §enormous amounts of electricity required §distribution from coastal plants expensive §dumping of concentrated brine, increases local salt concentration

20. Cloud Seeding §injecting large rain cloud with chemicals - silver iodide §water droplets in cloud clump around the chemical particles §forms ice §drops to earth as precipitation

21. Disadvantages §non availability of rain clouds §cloud seeding chemicals introduced into soil and water systems §ownership of water in clouds

22. Why ? §Reduce usage of waste water plants and septic systems §decrease pollution of surface water §reduce number of dams that destroy wildlife, displace people §slows depletion of aquifers

23. Curbing waste §evaporation, leaks, other losses

24. Reason for waste §artificially low water prices §external costs not included in monthly bills

25. Reducing irrigation losses §69% of water usage is for irrigation, §2/3 rd of this is wasted

26. Irrigation §3 different kinds

27. Gravity flow §water from aqueduct or nearby river §50 - 60 % efficiency §leveling of fields, surge flooding, capture and reuse runoff

28. Center Pivot §water pumped from underground and sprayed from mobile boom with sprinklers §70-80% efficiency

29. Drip irrigation §above or below ground pipes or tubes deliver water to individual plant roots §80 - 90% efficiency

30. Less wastage - Industry §use recycled water §machines designed to save water §Japan Israel

31. Most Wastage - Residences §water - used to flush toilets, wash hands, baths §green lawns in arid areas

32. Xeriscaping §vegetation adapted to dry climate §30-80% less water used

33. Solutions - Appendix 5 §water meter §repair leaky pipes §low flush toilets and showerheads §gray water for irrigation

34. Sustainable Usage - Case study §Columbia River Basin §World’s largest hydroelectric system §more than 100 dams §electricity prices - 40% lower §interferes with salmon life cycles

35. Salmon ranching §artificial hatcheries §genetic inbreeding §world’s largest program for ecosystem rehabilitation §cost - $2 billion §Time - 2 decades

36. Florida Everglades restoration §case study

37. Everglades §slow moving river §50 miles wide, 6 inches deep §flows south through Everglades National Park into Estuary at Florida Bay (Fig 17 -25)

38. World’s largest marshland § haven for 14 endangered or threatened species §(American alligator, Florida panther) §aquifer recharge, precipitation system

39. Problems - development - page 476 §straightening Kissimmee river §tremendous environmental impact

40. What can we do ? §Restore original path of Kissimmee §reclaim areas of wetlands §will cost $2 billion at the lower estimate