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

11. Aquifers §groundwater which flows through water saturated layers of sand, gravel, bedrock §replenished naturally by precipitation(natural recharge) §slow moving underground lakes

12. 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

13. Cone of depression §withdrawal rate of aquifer exceed natural recharge rate, §water table around withdrawal well lowered §creates a waterless volume §any pollution discharged onto land above will be pulled directly into well

14. Total Water Use

15. Amounts - US examples §100,000 = 1 car §1000 gal = 1lb of aluminum §800 gal = 1 LB of beef §26 gal = 2.2 lbs. paper §All nuclear plants require more water than Lake Eerie

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

17. Cause …freshwater shortages §dry climate §drought - §water stress §desiccation-overgrazing and deforestation §Africa,Middle East.S.Asia

18. Drought §at least 80 countries (40%) of world population experience year long droughts §since 1970’s - more than 24,000 dead

19. Water - political issue §150 of world’s 214 river systems shared by 2 countries §another 50 §by 3-10 nations

20. Water Resources in US - Case Study §East - energy production, cooling, manufacturing - flooding, occasional shortages, pollution §West - irrigation,water tables dropping, groundwater depleted faster than recharging

21. Increased water supply §build dams and reservoirs §withdraw groundwater §increase water efficiency

22. Living….. §Developed -favorable climate,bring in water from another watershed §Developing - must settle where water is available, borrow money to build dams and reservoirs

23. Constructing dams/reservoirs §water stored in large reservoirs §used for hydroelectric power, irrigate land downstream, control flooding, recreation

25. Examples - India §efficient irrigation let country become self sufficient in food, environmental problems with 1500 dam projects § still going ahead with 20 new dams in Gujerat - displace about 1 million people

26. India

27. Example -China §Three Gorges Project, world’s largest hydroelectric project, 370 mile reservoir ; power to 150 million Chinese,energy produced =18 nuclear power plants reduce dependence on coal, hold back Yangtze §flood 800 factories, displace 1.4 million people

28. Peoples Republic of China

29. Examples-Japan §inflatable small rubber dams, 1000 filled with air §can be deflected to allow accumulated silt to flow downstream

30. Case Study : Aswan Dam §Advantages - supplies electricity, irrigation §Disadvantages- silt accumulates, schistosomiasis §$100 million spent - fertilizers §expensive barrier dams §fishing industry collapsed

31. Case study : Watershed Transfer- California §maze of giant dams, pumps, aqueducts §transports water from N California to arid agricultural areas §irrigation for cotton, alfalfa uses as much water residential §needs of all 30 million Californians

32. Aqueducts

33. Case Study : James Bay Watershed Transfer §Quebec’s James and Hudson Bays §$60 billion, 50 year scheme to provide electricity §phase I completed, phase II indefinitely postponed

34. Case Study : Aral Sea §regional ecological disaster §shrinking and increased salinity as a result of irrigation water being diverted §all fish dead §salt, dust,pesticide residues carried by wind -salt rain

35. Withdrawing groundwater - US §being withdrawn at 4 times replacement level §1/2 of US drinking water and 40% of irrigation water from aquifers §Ogallala aquifer

36. Aquifer depletion §Saudi Arabia, Northern China, Northern Africa §withdrawal 10 times the recharge

37. Over use (fig 17- 18) §aquifer depletion aquifer subsidence §intrusion of salt water-water table lowered, normal interface between fresh and salt water moves inland

38. How can we slow this §not plant water thirsty crops in dry areas §develop crop strains that require less water §waste less irrigation water

39. 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

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

42. 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

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

44. Solutions §using water efficiently

45. Solutions §using water efficiently

46. 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

47. Curbing waste §evaporation, leaks, other losses

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

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

50. Irrigation §3 different kinds

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

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

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

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

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

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

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

58. 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

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

60. Florida Everglades restoration §case study

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

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

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

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