1. Freshwater Resources… Going…

3. 71% of Earth’s surface –97% saltwater –3% freshwater 2.6% ice caps and glaciers Only 0.014% of Earth’s total water supply is easily accessible as freshwater for human use

4. Surface water:

6. Watersheds the area of land where all of the water that is under it or drains off of it goes into the same place.

8. Should be a renewable resource, but…. Examples: –South Carolina vs. North Carolina –California –Colorado River –Aral Sea (and the Salton Sea)

11. Groundwater

13. NOT underwater lakes… Water fills cracks, fissures, and pore spaces

14. Ogallala Aquifer: World’s Largest

15. Tapping other groundwater – problems Saltwater Intrusion –Normal interface between freshwater and saltwater moves inland

17. Subsidence: –Land sinks –San Joaquin, CA (source = USGS) – Some parts of Mexico City sinking 1 inch per month.

18. Sinkholes –Roof of cavern collapses

20. Water can dissolve minerals and rocks…

21. Pollution: more expensive and difficult to clean up Septic Systems Animal “lagoons” Fracking Coal ash spills Landfill leaks Pesticides Sewer leaks Oil refinery “accidents” Etc etc etc!

22. Water Waste

24. Example of water waste: Household leaks can waste more than 1 trillion gallons annually nationwide. That's equal to the annual household water use of more than 11 million homes.

25. We use so much while much of the world suffers from Hydrological Poverty: –Approximately 1.4 billion people (POOR) living on less than $1 a day can not afford clean drinking water.

27. Why do we really waste so much? Underpricing! We don’t really pay for that much for it!

28. Conventional Irrigation: #1 Use of Water World Wide “About 60% of the irrigation water applied throughout the world does not reach targeted crops.” –Most lost to evaporation and run-off

29. Examples: 1. Flood irrigation:

30. 2. Conventional spray irrigation:

31. More efficient irrigation technologies include:

32. 1. Center Pivot/LEPA

33. LEPA: Low Energy Precision Application

34. 2. Drip Irrigation, Microirrigation

36. Other ways to reduce water waste:

37. 3. Xeriscaping Replace green lawns with vegetation adapted to the climate! (natural)

40. 4. Gray Water System

42. 5. Using storm run-off

44. This storm water system will reduce the building’s water bill by 90% and save water resources

45. In the U.S.: Flushing toilets with water clean enough to drink is the single largest use of domestic water.

46. U.S. Domestic Water Use

48. Solution: Desalination – Reverse osmosis: forcing water through a membrane (salt stays behind) – Distillation: boiling water (salt stays behind)

50. –Disadvantages: Expensive Energy Intensive Produces Briny Water

51. Zones of a lake

52. Zones of a river

53. The floodplain

54. People settle on floodplains because… Fertile soil (nutrient-rich silt from floods) Water for irrigation Transport Flat land

56. “controlling” flooding Channelization: straighten/deepen rivers Build levees Build dams Preserve wetlands

57. Dams China’s 3 Gorges

59. Good! “clean” electricity

60. Bad… Controls flooding downstream but floods upstream Displaced over a million people Seismic faults Disrupted ecosystems (river dolphin: ecologically extinct).