1. Water Use and Management

2. Water as a Resource Covers 71% of earth’s surface Important properties
Polar
Density
3 states of matter
High heat capacity

3. Available Water Total = 326 million cubic miles 97% in oceans
                                                                                                                    
                                                                                                                    
Available Water
Total = 326 million cubic miles
97% in oceans
2.997% is locked up in ice caps and glaciers
0.003% is easily accessible
Soil moisture
Groundwater
Water vapor
Lakes
Streams

4. Surface Water
Runoff flows into streams, lakes, wetlands and reservoirs
watershed
watershed.asp

5. Groundwater Precipitation infiltrates and percolates Zone of aeration
Pores, fractures, crevices, etc.
Zone of aeration
Zone of saturation
Top of this zone is water table
Falls and rises with weather

6. Water Compartments

7. Groundwater
Aquifers - Porous layers of sand, gravel, or rock lying below the water table.
Artesian - Pressurized aquifer intersects the surface. (Water flows without pumping)
Recharge Zones
Slow recharge rate

8. Groundwater

9. Use of Fresh Water United States China Agriculture Agriculture
Power plant cooling
Industry
Public
China
Agriculture
Industry
Public

10. Water Use Globally 70% agriculture (irrigation) 23% Industry
Domestic use (household, drinking water, sanitation) accounts for about 7%

11. Water Use According to the UN, the average person needs a minimum of:
1.3 gallons of water per day to survive in a moderate climate at an average activity level
13 gallons for drinking and cooking, bathing and sanitation
Average person in the US uses 100 gallons per day

12. FRESHWATER SHORTAGES
Estimated 1.5 billion people lack access to an adequate supply of drinking water.
Nearly 3 billion lack acceptable sanitation.
Globally, water supplies are abundant, but, along with capital resources, are unevenly distributed.

13. Freshwater Shortage Causes
Dry climate
Drought
Desiccation
deforestation & overgrazing
Water stress

14. Global Precipitation Patterns
Wright and Nebel, 2002.
Michael D. Lee Ph.D. Geography and Environmental Studies

15. Rainfall Distribution
Rain falls unevenly over the planet
Three factors control rainfall
Global atmospheric circulation-creates regions of high air pressure and low rainfall
Prevailing Winds-bring moisture to land from ocean; areas far from oceans are usually dry
Topography-mountains act as cloud formers and rain catchers

16. Rain Shadow Effect

17. Altering the Availability of Water
Levees-enlarged bank built up on each side of a river
Flood protection
Problems?

18. Altering the Availability of Water
Dikes
Flood protection from oceans
Dams and reservoirs
Human consumption
Electricity generation
Flood control
Recreation

19. Dams and Reservoirs Cons
Environmental Costs
Upsets natural balance of water systems
Croplands downstream are deprived of nutrient rich silt
Evaporation
Ecosystem Losses
Loss of wildlife habitat
Migration and spawning of fish disrupted
Flooded land destroys forests or cropland
Displacement of People

20. Colorado River Basin Diversion of water from Colorado River
Disputes between AZ, CA, Mexico
Dams trap silt more fertilizer needed
High levels of NaCl salinization

21. Three Gorges Dams in China is forcing relocation of 1.2 million people
Yangtze river

22. Tapping Groundwater Supplies
About ½ of the drinking water in the US is pumped from aquifers
Advantages
Year-round use
Renewable if not overpumped or contaminated
No evaporation losses
Often less expensive

23. Tapping Groundwater Supplies
Disadvantages
Water table lowering
Overpumping
Sinking of land (subsidence) when water removed
Chemical contamination
Saltwater intrusion

24. Cone of Depression and Saltwater Intrusion

25. Ogallala Aquifer Underlies 8 states from SD to TX
Held more water than all freshwater on Earth
Water shortages
Largest in the US

26. Desalinization Removing salt from sea water
Distillation-heat boils water; leaves salt behind
Reverse osmosis-water forced through semi-permeable membrane at high pressure

27. Towing Icebergs Carry fresh water to places that need it
How can it be done? Would it be economically sound?

28. Water Efficiency and Conservation
Change in personal habits
Fix leaky pipes
Water–saving toilets, faucets, & shower heads
Plant drought–tolerant vegetation in residential communities located in arid & semi–arid areas
Increase efficiency of irrigation
drip irrigation, computer monitoring, center-pivot
Use recycled water
treat gray water from showers, washing machines for reuse
Education
Eat less meat