1. 13 Water

2. Overview of Chapter 13  Importance of Water  Water Use and Resource Problems  Water Problems in US and Canada  Global Water Problems  Water Management  Water Conservation © 2012 John Wiley & Sons, Inc. All rights reserved.

3. Importance on APES test  Earth Systems and Resources (10-15%) Global Water Resources and Use (Freshwater/saltwater; agricultural, industrial, and domestic use; surface and groundwater issues; global problems; conservation) © 2012 John Wiley & Sons, Inc. All rights reserved.

4. Importance of Water  Cooking & washing  Agriculture  Manufacturing  Mining  Energy production  Waste disposal  Use of freshwater is increasing © 2012 John Wiley & Sons, Inc. All rights reserved.

5. Properties of Water  Composed of 2 Hydrogen and 1 oxygen  Exists as solid, liquid or gas  High heat capacity  Polar  Forms Hydrogen bond between 2 water molecules  H-bonds define water’s physical properties © 2012 John Wiley & Sons, Inc. All rights reserved.

6. Properties of Water  Water is never completely pure in nature  Content of seawater (left)  Many substances water dissolves cause water pollution © 2012 John Wiley & Sons, Inc. All rights reserved.

7. Distribution of Water  Only 2.5% of water on earth is freshwater  2% of this in the form of ice  Only ~0.5% of water on earth is available freshwater © 2012 John Wiley & Sons, Inc. All rights reserved.

8. Hydrologic Cycle © 2012 John Wiley & Sons, Inc. All rights reserved.

9. Freshwater Terminology  Surface water  Precipitation that remains on the surface and does not seep into soil  Runoff  Movement of surface water to lakes, rivers, etc.  Watershed (drainage basin)  Land area that delivers water into a stream or river system  Groundwater  Freshwater under the earth’s surface stored in aquifers  Aquifer  Underground caverns and porous layers of sand, gravel and rock in which groundwater is stored © 2012 John Wiley & Sons, Inc. All rights reserved.

11. Mississippi River Watershed is the largest in U.S. How does a cattle farmer in Montana potentially impact a shrimp fisherman in Louisiana? RIVER SYSTEM

12. Did You Know? The Mississippi River Basin covers 3 million square kilometers (1.2 million sq mi), making it the third largest watershed in the world. It drains 41% of the land area of the contiguous US.

13. World’s River Systems and Watershed

14. Groundwater  As precipitation infiltrates and percolates through voids in soil and rock  Pores, fractures, crevices, etc.  Shallow rock has little moisture  Zone of saturation is at a depth were ground is filled with water  Top of this zone is water table.  Falls in dry weather  Rises in wet weather

15. Aquifer  Important source of water  Porous, water-saturated layers of sand, gravel or bedrock through which groundwater flows  Area of land that supplies water to aquifer is called the recharge area  Natural recharge is when water percolates downward, but sometimes lateral recharge occurs

16. Freshwater Aquifer © 2012 John Wiley & Sons, Inc. All rights reserved.

18. Aquifer: a water-bearing rock formation

19. Porosity  How much space (pores) or holes found in rock  Where water can flow through  Porous rock can hold lots of water

20. Water Use and Resource Problems  Fall into Three Categories  Too much water  Too little water  Poor quality/contamination (addressed in Chapter 21) © 2012 John Wiley & Sons, Inc. All rights reserved.

21. Too Much Water  Flooding  Both natural and human-induced  Modern floods are highly destructive  Humans have removed water-absorbing plant cover from soil  Humans construct buildings on floodplains  Floodplain  Area bordering a river channel that has the potential to flood © 2012 John Wiley & Sons, Inc. All rights reserved.

22. Urban vs. Pre-Urban Floodplains © 2012 John Wiley & Sons, Inc. All rights reserved.

23. Floodplains  Rather than rebuild levees adjacent to rivers, experts suggest allowing some flooding of floodplains during floods.  Government restrictions on building  Levees can fail © 2012 John Wiley & Sons, Inc. All rights reserved.

24. Left: Traditional levees adjacent to river Right: Suggested levee style, set back from river © 2012 John Wiley & Sons, Inc. All rights reserved.

25. Floods of Summer 2008 © 2012 John Wiley & Sons, Inc. All rights reserved.

26. Levees produce major challenges © 2012 John Wiley & Sons, Inc. All rights reserved. Floodwaters can no longer add fertility to flood plains by depositing sediment Sediments are carried farther downstream and settle out where the river enters the ocean. Prevent flooding at one location, but they force floodwater farther downstream and cause worse flooding. Levees break due to pressure which was what happened during Hurricane Katrina in 2005 in New Orleans

27. Too Little Water  Typically found in arid land  Problems  Drought  Overdrawing water  for irrigation purposes  Aquifer depletion Subsidence Sinkholes © 2012 John Wiley & Sons, Inc. All rights reserved.

28. Too Little Water  Saltwater Intrusion © 2012 John Wiley & Sons, Inc. All rights reserved.

29. Water Problems In US and Canada  Overall, US has a plentiful supply of freshwater  Many areas have a severe shortages  Geographical variations  Seasonal variations © 2012 John Wiley & Sons, Inc. All rights reserved.

30. Water Problems In US and Canada  Water shortages in West and Southwest  Water is diverted and transported via aqueducts © 2012 John Wiley & Sons, Inc. All rights reserved.

31. Water Problems in US and Canada- Surface Water  Mono Lake (Eastern CA)  Rivers and streams that once fed this lake are diverted to Los Angeles (275mi away)  Becoming highly saline  Court ordered water diversion reduction  Colorado River Basin  Provides water for 27-million people  Numerous dams for Hydropower  Colorado River no longer reaches ocean © 2012 John Wiley & Sons, Inc. All rights reserved.

32. Colorado River bed in Mexico © 2012 John Wiley & Sons, Inc. All rights reserved.

33. Water Problems in US and Canada- Groundwater  Aquifer Depletion © 2012 John Wiley & Sons, Inc. All rights reserved.

34. Water Problems in US and Canada- Groundwater  Ogallala Aquifer  High Plains  Water withdrawn for agriculture faster than nature replaces it © 2012 John Wiley & Sons, Inc. All rights reserved.

35. WYOMINGSOUTH DAKOTA NEBRASKA COLORADO KANSAS OKLAHOMA NEW MEXICO TEXAS 0100 Miles Kilometers Less than 61 meters (200 ft) 61-183 meters (200-600 ft) More than 183 meters (600 ft) (as much as 370 meters or 1,200 ft. in places) 0160 Ogallala Aquifer: World’s largest known aquifer. (If all water from this aquifer was on the surface, it would cover all 50 states with 1.5 feet of water!) Being severely depleted over time.

36. Global Water Problems  Amount of freshwater on planet CAN meet human needs  BUT, it is unevenly distributed and some places lack stable runoff  Problems:  Weather and Climate  Drinking Water  Population Growth  Sharing Water Resources Among Countries © 2012 John Wiley & Sons, Inc. All rights reserved.

37. Global Water Problems  Water and Climate  Climate change affects the type and distribution of precipitation  Potential issues: Reduced snowfall will impact water resources downstream Sea level rise will cause saltwater intrusion into drinking water supplies © 2012 John Wiley & Sons, Inc. All rights reserved.

38. Global Water Problems  Drinking Water Problems  Many developing countries have insufficient water to meet drinking and household needs  1.1 billion people lack access to safe drinking water  Population Growth  Increase in population means an increase in freshwater requirements  Limits drinking water available  Limits water available for agriculture (food) © 2012 John Wiley & Sons, Inc. All rights reserved.

39. Global Water Problems  Sharing Water Resources Among Countries  Rhine River Basin (right) Countries upstream discharged pollutants into river Countries downstream had to pay to clean the water before they could drink it  Aral Sea (next slide) Water diversion for irrigation has caused sea to become too saline © 2012 John Wiley & Sons, Inc. All rights reserved.

40. Aral Sea © 2012 John Wiley & Sons, Inc. All rights reserved. 19762010

41. Global Water Problems © 2012 John Wiley & Sons, Inc. All rights reserved.

42. Water Management  Main Goal: Provide sustainable supply of high- quality water  Dams and Reservoirs  Water Diversion Projects  Desalinization © 2012 John Wiley & Sons, Inc. All rights reserved.

43. Dams and Reservoirs  Benefits:  Ensure year-round supply of water with regulated flow  Generate electricity  Provide recreational activities  Disadvantages  Alter the ecosystem  Reduce sediment load © 2012 John Wiley & Sons, Inc. All rights reserved.

44. Upstream of Dams - Negative Impact  Environment  Loss of terrestrial habitat and species  Creation of artificial (lakes) system  Exotic species introductions  Reservoir/storage for contaminants  Cultural / social  Loss of cultural resources  Displacement of families (villages, regions)  Water quality hazard  Economic  Shift in land use / economy  Water loss via evaporation  Water loss via seepage  Aesthetic  landscape inundated

45. Downstream Impacts of Dams  Altered hydrology - no seasonality  Altered water quality/character  Modify nutrient cycling  Reduce sediment supply  Channel adjustments  Habitat modification  Species impacts  River fragmentation

46. Dams and Reservoirs  Glen Canyon Dam  Powerful spring floods brought sediment, which created sandbar habitat  Regulated flow is detrimental to wildlife  To rectify this, government started flooding the Grand Canyon periodically starting in 1996 © 2012 John Wiley & Sons, Inc. All rights reserved.

47. Dams and Reservoirs © 2012 John Wiley & Sons, Inc. All rights reserved.

48. Dams and Reservoirs  Salmon Population in Columbia R. very low due to dams that impede migration  Fish ladders help, but are not effective enough © 2012 John Wiley & Sons, Inc. All rights reserved.

49. Large losses of water through evaporation Large losses of water through evaporation Flooded land destroys forests or cropland and displaces people Flooded land destroys forests or cropland and displaces people Downstream flooding is reduced Downstream cropland and estuaries are deprived of nutrient-rich silt Downstream cropland and estuaries are deprived of nutrient-rich silt Reservoir is useful for recreation and fishing Can produce cheap electricity (hydropower) Migration and spawning of some fish are disrupted Provides water for year-round irrigation of cropland Pros and Cons of Dams

50. Water Diversion Projects  Water diverted to areas that are deficient  Much of Southern CA receives its water supply from diverted water from Northern CA  Controversial and expensive © 2012 John Wiley & Sons, Inc. All rights reserved.

51. Desalinization  Removal of salt from ocean or brackish water  Two methods:  Distillation - salt water is evaporated, and water vapor is condensed into freshwater  Reverse Osmosis- involves forcing salt water through a membrane permeable to water, but not salt  Very expensive © 2012 John Wiley & Sons, Inc. All rights reserved.

52. Desalinization Removing salt from salt water  Has a lot of promise  Very energy intensive  Very expensive  What to do with waste?  Future?

53. Water Conservation  Reducing Agricultural Water Waste  4 types of irrigation. Furrow irrigation - Dig trenches along the crop rows and fill them with water. Flood irrigation involved flooding an entire field with water. More disruptive to plant growth. Spray irrigation- Water is pumped from a well into an apparatus that contains a series of spray nozzles that spray water across the field. Micro-irrigation - irrigation that conserves waster by piping to crops through sealed systems. AKA drip or trickle irrigation. © 2012 John Wiley & Sons, Inc. All rights reserved.

54. Water Conservation Drip irrigation © 2012 John Wiley & Sons, Inc. All rights reserved. Furrow irrigation Flood Irrigation Spray Irrigation

55. Water Conservation  Reducing Industrial Water Waste  Stricter laws provide incentive to conserve water  Water scarcity encourages further industrial recycling  Potential to conserve water is huge © 2012 John Wiley & Sons, Inc. All rights reserved.

56. Water Conservation  Reducing Municipal Water Waste  Gray Water  Can be used to flush toilets, wash car or water lawn  Water saving household fixtures  Government incentives © 2012 John Wiley & Sons, Inc. All rights reserved.

57. Conserving at Home  Install water-saving shower heads and faucets  Install low-flush toilets  Fix leaky fixtures  Purchase high efficiency appliances  Modify personal habits  Use the dishwasher instead of washing by hand © 2012 John Wiley & Sons, Inc. All rights reserved.