1. “Our liquid planet glows like a soft blue sapphire in the hard-edged darkness of space. There is nothing else like it in the solar system. It is because of water." [John Todd]

3. Water Resources
Chapter 13

4. Core Case Study: Water Conflicts in the Middle East: A Preview of the Future
Water shortages in the Middle East: hydrological poverty
Nile River
Jordan Basin
Tigris and Euphrates Rivers
Peacefully solving the problems

5. Freshwater Is an Irreplaceable Resource That We Are Managing Poorly
Why is water so important?
Earth as a watery world: 71%
(Freshwater availability: 0.024%)
Poorly managed resource
Water pollution

6. Most of the Earth’s Freshwater Is Not Available to Us
Hydrologic cycle
Movement of water in the seas, land, and air
Driven by solar energy and gravity
People divided into
Water haves
Water have-nots

7. We Get Freshwater from Groundwater and Surface Water
Zone of saturation
Water table
Aquifers
Natural recharge
Lateral recharge

8. Cont’d Surface Water Surface runoff Watershed (drainage) basin
Reliable runoff
1/3 of total

9. We Use a Large and Growing Portion of the World’s Reliable Runoff
2/3 of the surface runoff: lost by seasonal floods
1/3 runoff usable
Domestic: 10%
Agriculture: 70%
Industrial use: 20%
Fred Pearce, author of When the Rivers Run Dry

10. Case Study: Freshwater Resources in the United States
More than enough renewable freshwater, unevenly distributed
Effect of
Floods
Pollution
Drought

11. 2007: U.S. Geological Survey projection
Water hotspots

12. Water Shortages Will Grow
Dry climate
Drought
Too many people using a normal supply of water
Wasteful use of water
China and urbanization
Hydrological poverty
US Drought Monitor

13. Natural Capital Degradation: Stress on the World’s Major River Basins

14. Long-Term Severe Drought Is Increasing
Causes
Extended period of below-normal rainfall
Diminished groundwater
Harmful environmental effects
Dries out soils
Reduces stream flows
Decreases tree growth and biomass
Lowers net primary productivity and crop yields
Shift in biomes

15. In Water-Short Areas Farmers and Cities Compete for Water Resources
2007: National Academy of Science study
Increased corn production in the U.S. to make ethanol as an alternative fuel
Decreasing water supplies
Aquifer depletion
Increase in pollution of streams and aquifers

16. Who Should Own and Manage Freshwater Resources?
Most water resources
Owned by governments
Managed as publicly owned resources
Veolia and Suez: French companies
Buy and manage water resources
Successful outcomes in many areas

17. Poor water management in Bolivia A subsidiary of Bechtel Corporation
Cont’d
Bechtel Corporation
Poor water management in Bolivia
A subsidiary of Bechtel Corporation
Poor water management in Ecuador
Potential problems with full privatization of water resources
Financial incentive to sell water; not conserve it
Poor will still be left out
Blue Gold

18. Water Tables Fall When Groundwater Is Withdrawn Faster Than It Is Replenished
India, China, and the United States
Three largest grain producers
Overpumping aquifers for irrigation of crops
India and China
Small farmers drilling tubewells
Effect on water table
Saudi Arabia
Aquifer depletion and irrigation

19. Natural Capital Degradation: Irrigation in Saudi Arabia Using an Aquifer

20. Trade-Offs: Withdrawing Groundwater, Advantages and Disadvantages

21. Case Study: Aquifer Depletion in the United States
Ogallala aquifer: largest known aquifer
Irrigates the Great Plains
Water table lowered more than 30m
Cost of high pumping has eliminated
some of the farmers
Government subsidies to continue
farming deplete the aquifer further
Biodiversity threatened in some areas

22. California Central Valley: serious water depletion

23. Solutions: Groundwater Depletion, Using Water More Sustainably

24. Active Figure: Threats to aquifers
Salt Water Intrusion

25. Large Dams and Reservoirs Have Advantages and Disadvantages
Main goals of a dam and reservoir system
Capture and store runoff

26. Fill up with sediment within 50 years

27. The Ataturk Dam Project in Eastern Turkey

28. Some Rivers Are Running Dry and Some Lakes Are Shrinking
Dams disrupt the hydrologic cycle
Major rivers running dry part of the year
Colorado and Rio Grande, U.S.
Yangtze and Yellow, China
Indus, India
Danube, Europe
Nile River-Lake Victoria, Egypt
Lake Chad Africa: disappearing

29. Case Study: The Colorado River Basin— An Overtapped Resource
2,300 km through 7 U.S. states
14 Dams and reservoirs
Located in a desert area within the rain shadow of the Rocky Mountains
Water supplied mostly from snowmelt of the Rocky Mountains
Supplies water and electricity for more than 25 million people
Irrigation of crops
Recreation

30. Colorado River basin has very dry lands
continued
Four Major problems
Colorado River basin has very dry lands
Modest flow of water for its size
Legal pacts allocated more water for human use than it can supply
Amount of water flowing to the mouth of the river has dropped
What will happen if some of the reservoirs empty out?
Economic and ecological catastrophe
Political and legal battles over water

31. The Colorado River Basin
Aerial View of Glen Canyon Dam
Across the Colorado River and Lake Powell

32. The Flow of the Colorado River Measured at Its Mouth Has Dropped Sharply

33. Case Study: China’s Three Gorges Dam
World’s largest hydroelectric dam and reservoir
2 km long across the Yangtze River
Benefits
Electricity-producing potential is huge
Holds back the Yangtze River floodwaters
Allows cargo-carrying ships
Skip

34. Skip Harmful effects Displaces about 5.4 million people
continued
Harmful effects
Displaces about 5.4 million people
Built over a seismic fault
Significance?
Rotting plant and animal matter producing CH4
Worse than CO2 emissions
Will the Yangtze River become a sewer?
Skip

35. CA, U.S., Transfers Water from Water-Rich Areas to Water-Poor Areas
Water transferred by
Tunnels
Aqueducts
Underground pipes
May cause environmental problems
California Water Project

36. California Central Valley: serious water depletion

37. The California Water Project and the Central Arizona Project

38. Case Study: The Aral Sea Disaster
Large-scale water transfers in dry central Asia
Salinity
Wetland destruction and wildlife
Fish extinctions and fishing
Wind-blown salt
Water pollution
Climatic changes
Restoration efforts

39. 1976
2006
Figure 13.18
Natural capital degradation: the Aral Sea was once the world’s fourth largest freshwater lake. Since 1960, it has been shrinking and getting saltier because most of the water from the rivers that replenish it has been diverted to grow cotton and food crops (Concept 13-4). These satellite photos show the sea in 1976 and in It has split into two major parts, little Aral on the left and big Aral on the right. As the lake shrank, it left behind a salty desert, economic ruin, increasing health problems, and severe ecological disruption. Question: What do you think should be done to help prevent further shrinkage of the Aral Sea?
Stepped Art
Fig a, p. 331

40. Ship Stranded in Desert Formed by Shrinkage of the Aral Sea

41. China Plans a Massive Transfer of Water
South-North Water Transfer Project
Water from three rivers to supply 0.5 billion people
Completion in about 2050
Impact
Economic
Health
Environmental
Skip

42. Solutions Removing Salt from Seawater Seems Promising but Is Costly
Desalination
Distillation
Reverse osmosis, microfiltration
15,000 plants in 125 countries
Saudi Arabia: highest number
Problems
High cost and energy footprint
Keeps down algal growth and kills many marine organisms
Large quantity of brine wastes
Future economics

43. Put simply, desalination purifies water by removing dissolved mineral salts and other solids. In the Middle East, most desalted water is produced by means of distillation, which imitates the natural water cycle: Salt water is heated to produce water vapor, which then condenses to form freshwater. American desalination plants favor a different technology -- reverse osmosis -- which forces the water through a series of membranes, leaving the salts behind.

44. Animation . . .

45. Science Focus: The Search for Improved Desalination Technology
Desalination on offshore ships
Solar or wind energy
Better membranes
Better disposal options for the brine waste
Reduce water needs, conserve water

46. Reducing Water Waste Has Many Benefits
Water conservation
Improves irrigation efficiency
Improves collection efficiency
Uses less in homes and businesses
Worldwide: 65–70% loss
Evaporation, leaks, etc.
Water prices: low cost to user
Government subsidies: more needed?

47. We Can Cut Water Waste in Irrigation
Flood irrigation
Wasteful
Center pivot, low pressure sprinkler
Low-energy, precision application sprinklers
Drip or trickle irrigation, microirrigation
Costly; less water waste
“more crop per drop”

48. Major Irrigation Systems

49. Solutions: Reducing Irrigation Water Waste

50. Developing Countries Use Low-Tech Methods for Irrigation
Human-powered treadle pumps
Harvest and store rainwater
Create a canopy over crops: reduces evaporation
Fog-catcher nets

51. We Can Cut Water Waste in Industry and Homes
Recycle water in industry
Fix leaks in the plumbing systems
Use water-thrifty landscaping: xeriscaping
Use gray water
Pay-as-you-go water use

52. Solutions: Reducing Water Waste

53. We Can Use Less Water to Remove Wastes
Can we mimic how nature deals with waste?
Waterless composting toilets

54. We Need to Use Water More Sustainably
“The frog does not drink up the pond in which it lives”
Blue revolution

55. What Can You Do? Water Use and Waste

56. Some Areas Get Too Much Water from Flooding
Flood plains
Highly productive wetlands
Provide natural flood and erosion control
Maintain high water quality
Recharge groundwater
Benefits of floodplains
Fertile soils
Nearby rivers for use and recreation
Flatlands for urbanization and farming

57. Dangers of floodplains and floods Deadly and destructive
continued
Dangers of floodplains and floods
Deadly and destructive
Human activities worsen floods
Failing dams and water diversion
Hurricane Katrina and the Gulf Coast
Removal of coastal wetlands

58. Natural Capital Degradation: Hillside Before and After Deforestation

59. Case Study: Living Dangerously on Floodplains in Bangladesh
Dense population
Located on coastal floodplain
Moderate floods maintain fertile soil
Increased frequency of large floods
Effects of development in the Himalayan foothills
Destruction of coastal wetlands

60. We Can Reduce Flood Risks
Rely more on nature’s systems
Wetlands
Natural vegetation in watersheds
Rely less on engineering devices
Dams
Levees
LA River Revitilization

61. Solutions: Reducing Flood Damage