Water Resources

1. QODCalculate how many liters of water are wasted in 1 month by a faucet that leaks 2 drops of water per second.(1 liter of water equals about 3500 drops)How many gallons is this?(1 liter equals 0.265 gallons)

2. Water Resources G. Tyler Miller’s Living in the Environment 13th Edition Chapter 14

3. Key Concepts • The physical properties of water • Availability of fresh water • Methods of increasing freshwater supplies • Using water more efficiently • Problems associated with flooding

4. Water’s Unique Properties Hydrogen bonding Major factor in determining water’s unique properties

5. - - - - - - O O O H H H H H H + + + + + + Hydrogen bonds Covalent bonds

6. Water’s Unique Properties Liquid over wide temperature range High boiling point 100°C (212°F) Low freezing point 0°C (32°F) Changes temperature slowly Helps protect organisms Moderates the earth’s climate Excellent coolant High heat of evaporation Absorbs heat as it changes into water vapor Releases heat as vapor condenses

7. Water’s Unique Properties Great dissolving power Carries dissolved nutrients into tissue Flush waste products out of tissue All-purpose cleanser Remove and dilute water-soluble wastes pH Helps maintain balance between acids and bases Adhesion and cohesion Surface tension Wetting ability Expands when it freezes Ice floats

8. Water: A Vital Resource Fresh Water 2.6% Oceans and saline lakes 97.4%

9. Supply of Water Resources Freshwater Readily accessible freshwater Groundwater 0.592% Biota 0.0001% Lakes 0.007% Rivers 0.0001% 0.014% Ice caps and glaciers 0.1.984% Soil moisture 0.005% Atmospheric water vapor 0.001%

10. Surface Water Surface runoff Water flowing off the land into bodies of water Reliable runoff One-third of world’s annual runoff Represents a stable source of water Watershed (Drainage Basin) Region from which water drains

11. Groundwater

12. Ground Water Fig. 14-3 p. 315 Flowing artesian well Unconfined Aquifer Recharge Area Precipitation Evaporation and transpiration Well requiring a pump Evaporation Confined Recharge Area Runoff Aquifer Stream Infiltration Water table Lake Infiltration Unconfined aquifer Confined aquifer Less permeable material such as clay Confirming permeable rock layer

13. Use of Water Resources United States Agriculture 41% Power cooling 38% Industry 11% Public 10% • Humans use about 50% of reliable runoff • Agriculture • Industry • Domestic • Power Plants

14. 5,500 5,000 4,500 4,000 3,500 3,000 Water use (cubic kilometers per year) 2,500 2,000 1,500 1,000 500 1900 1920 1940 1960 1980 2000 Total use Agricultural use Industrial use Domestic use Year

15. Water in the United States Average precipitation (top) in relation to water-deficit regions and their proximity to metropolitan areas (bottom).

16. Too Little Water Acute shortage Adequate supply Shortage Metropolitan regions with population greater than 1 million • Dry climate • Air circulation patterns • Drought • 21 days+ • Precipitation <70% • Increased evaporation • Desiccation • Drying of the soil • Water stress • Low per capita availability • Caused by increased population • Limited runoff levels

17. Water stressed – reliable runoff per person below 1700 cu meters per year Water scarcity – per capita availability below 1000 cu meter per year • 500 million people live in countries that are either water stressed or water scarce • limited access (live far away) • arrives during short periods • hydrological poverty • Collect water from unsafe sources • Purchase from private vendor

18. Increasing Fresh Water Supplies Build dams and reservoirs to store runoff Bring surface water from another area Withdraw groundwater. Convert salt water to fresh water Waste less water Import food to reduce water use

19. Using Dams and Reservoirs to Supply More Water(To Dam or Not To Dam)

20. Provides water for year-round irrigation of cropland Flooded land destroys forests or cropland and displaces people Large losses of water through evaporation Provides water for drinking Downstream cropland and estuaries are deprived of nutrient-rich silt Reservoir is useful for recreation and fishing Risk of failure and devastating downstream flooding Can produce cheap electricity (hydropower) Downstream flooding is reduced Migration and spawning of some fish are disrupted Fig. 14-13a, p. 317

21. Ecological Services of Rivers • Deliver nutrients to the sea which helps to sustain coastal fisheries • Deposit silt that maintains deltas • Purify water • Renew and nourish wetlands • Provide habitats for aquatic life • Conserve species diversity

22. Beijing RUSSIA YELLOW SEA MONGOLIA CHINA Shanghai Wunan Jailing River Yichang Chongquing Yangtze River CHINA Three Gorges Dam Reservoir EAST CHINA SEA NEPAL BHUTAN BANGLADESH PACIFIC OCEAN VIETNAM INDIA BURMA LAOS China’s Three Gorges Dam

23. Case Study: The Colorado Basin – an Overtapped Resource Lake Powell, is the second largest reservoir in the U.S. It hosts one of the hydroelectric plants located on the Colorado River.

24. IDAHO WYOMING Dam The Colorado River Basin Aqueduct or canal Salt Lake City Grand Junction Upper Basin Denver Lower Basin UPPER BASIN UTAH COLORADO Lake Powell Grand Canyon Glen Canyon Dam Las Vegas NEW MEXICO Boulder City ARIZONA CALIFORNIA Albuquerque LOWER BASIN Los Angeles Palm Springs Phoenix 0 100 mi. San Diego Yuma 0 150 km Mexicali Tucson All-American Canal Gulf of California MEXICO

25. Transferring Water from One Place to Another CALIFORNIA NEVADA UTAH Shasta Lake Sacramento River Sacramento North Bay Aqueduct San Francisco Fresno South Bay Aqueduct Colorado River Los Angeles Aqueduct ARIZONA California Aqueduct Central Arizona Project Los Angeles Phoenix San Diego Colorado River Aqueduct Tucson MEXICO Watershed transfer • California Water Project • Central Arizona Project • James Bay (Canada)

26. Increasing Fresh Water Supplies Build dams and reservoirs to store runoff Bring surface water from another area Withdraw groundwater.

27. Tapping Groundwater Advantages Year-round use No evaporation losses Often less expensive Potential Problems! Many

28. Problems with Using Groundwater Original water table Initial water table Cone of depression Lowered water table • Water Table Lowering

29. Problems with Using Groundwater WYOMING SOUTH DAKOTA 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) NEBRASKA KANSAS COLORADO OKLAHOMA NEW MEXICO TEXAS Miles 0 100 0 160 Kilometers • Aquifer depletion • Ogalala Aquifer

30. Problems with Using Groundwater • Subsidence • Sinking of land when groundwater is withdrawn

31. Other Effects of Groundwater Overpumping Sinkholes form when the roof of an underground cavern collapses after being drained of groundwater.

32. Problems with Using Groundwater Major irrigation well Well contaminated with saltwater Water table Sea Level Salt water Fresh groundwater aquifer Interface Interface Saltwater Intrusion Normal Interface • Saltwater intrusion

33. Major irrigation well Well contaminated with saltwater Water table Sea level Fresh groundwater aquifer Saltwater Seafloor Interface Saltwater intrusion Interface Normal interface Fig. 14-11, p. 315

34. Problems with Using Groundwater • Chemical contamination • Reduced stream flow • Tragedy of the commons

35. Converting Salt Water to Fresh Water Desalination – removing dissolved salts from ocean water or brackish water. Distillation desalination Heating salt water until it evaporates. Reverse osmosis desalination Salt water is pumped at high pressure through a thin membrane

36. Converting Salt Water to Fresh Water Desalination – removing dissolved salts from ocean water or brackish water. Desalination is very expensive Larger amounts of energy needed Desalination produces large quantities of wastewater waste disposal problem

37. Making it Rain Cloud Seeding Water condensation nuclei Silver iodide particles Limited Success Not useful in dry areas Potential pollution from cloud seeding chemicals Legal disputes: ownership of clouds

38. Using Water More Efficiently Reduce losses due to leakage 60 to75% of water people use is lost! Causes of waste Water subsidy policy Artificially low cost of water False sense of abundance

39. Using Water More Efficiently Causes of waste cont. Water laws Doctrine of riparian rights (East) Anyone owning land adjoining stream has right to water Principle of prior appropriation (West) First-come, first-served Common law governs groundwater Subsurface water belongs to whoever owns the land above it Fragmented watershed management

40. Drip irrigation (efficiency 90–95%) Gravity flow (efficiency 60% and 80% with surge valves) Center pivot (efficiency 80%–95%) Water usually pumped from underground and sprayed from mobile boom with sprinklers. Above- or below-ground pipes or tubes deliver water to individual plant roots. Water usually comes from an aqueduct system or a nearby river. Fig. 14-18, p. 325

41. Too Much Water: Floods • Natural phenomena • heavy rain, melting snow • Aggravated by human activities • Renew and replenish Reservoir Dam Levee Flood wall Floodplain

42. Solutions: Achieving a More Sustainable Water Future • Efficient irrigation • Water-saving technologies • Improving water management

43. What Can You Do? Water Use and Waste • Use water-saving toilets, showerheads, and faucet aerators. • Shower instead of taking baths, and take short showers. • Stop water leaks. • Turn off sink faucets while brushing teeth, shaving, or washing. • Flush toilets only when necessary. • Wash only full loads of clothes or use the lowest water-level for smaller loads. • Use recycled (gray) water for lawn, gardens, house plants, car washing. • Wash a car from a bucket of soapy water, and use the hose for rinsing only. • If you use a commercial car wash, try to find one that recycles its water. • Replace your lawn with native plants that need little if any watering and decorative gravel or rocks. • Water lawns and gardens in the early morning or evening. • Sweep or blow off driveways instead of hosing off with water. • Use drip irrigation and mulch for gardens and flowerbeds.

44. 2002 Free Response Question #2