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Water Resources Slide 2 Key Concepts The physical properties of water Availability of fresh water Methods of increasing freshwater supplies Using water more efficiently Problems associated with flooding Slide 3 Waters Unique Properties Hydrogen bonding Liquid over wide temperature range Changes temperature slowly High heat of evaporation Great dissolving power Filters out ultraviolet radiation Adhesion and cohesion Expands when it freezes Slide 4 Hydrogen Bonding in Ice Slide 5 Hydrogen Bonding in Water Slide 6 All waterFresh waterReadily accessible fresh water Oceans and saline lakes 97.4% Fresh water 2.6% Groundwater 0.592% Ice caps and glaciers 1.984% Lakes 0.007% Soil moisture 0.005% Biota 0.0001% Rivers 0.0001% Atmospheric water vapor 0.001% 0.014% Lakes 0.007% Soil moisture 0.005% Ice caps and glaciers 1.984% Oceans and saline lakes 97.4% Supply of Water Resources Slide 7 Supply of Freshwater Resources Freshwater Readily accessible freshwater Biota 0.0001% Biota 0.0001% Rivers 0.0001% Rivers 0.0001% Atmospheric water vapor 0.0001% Atmospheric water vapor 0.0001% Lakes 0.0007% Soil moisture 0.0005% Groundwater 0.592% Groundwater 0.592% Ice caps and glaciers 1.984% 0.014% Slide 8 Surface Water Surface runoff Watersheds Reliable runoff Slide 9 Evaporation and transpiration Evaporation Stream Infiltration Water table Infiltration Unconfined aquifer Confined aquifer Lake Well requiring a pump Flowing artesian well Runoff Precipitation Confined Recharge Area Aquifer Less permeable material such as clay Confirming permeable rock layer Ground Water Slide 10 Water Budget Slide 11 Use of Water Resources Humans use about 54% of reliable runoff Agriculture Industry Domestic Power plants United States Industry 11% Public 10% Power cooling 38% Agriculture 38% Slide 12 1 automobile 1 kilogram cotton 1 kilogram aluminum 1 kilogram grain-fed beef 1 kilogram rice 1 kilogram corn 1 kilogram paper 1 kilogram steel 400,000 liters (106,000 gallons) 10,500 liters (2,400 gallons) 9,000 liters (2,800 gallons) 7,000 liters (1,900 gallons) 5,000 liters (1,300 gallons) 1,500 liters (400 gallons) 880 liters (230 gallons) 220 liters (60 gallons) Slide 13 Too Little Water Dry climate Drought Desiccation Water stress Acute shortage Adequate supply Shortage Metropolitan regions with population greater than 1 million Slide 14 Average annual precipitation (centimeters) Less than 41 41-81 81-22 More than 122 Slide 15 Acute shortage Shortage Adequate supply Metropolitan regions with population greater than 1 million Slide 16 Freshwater Stress Slide 17 Slide 18 Using Dams and Reservoirs to Supply More Water: The Trade-offs 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 Slide 19 Slide 20 Pueblo Dam, Colorado Slide 21 Silt filled Reservoir behind a Dam Slide 22 Highly likely conflict potential Substantial conflict potential Moderate conflict potential Unmet rural water needs Wash. Oregon Idaho Nevada California Utah Montana Wyoming Colo. N.M. N.D. S.D. Neb. Kansas Oak. Texas Slide 23 HighNone North America South America Stress Africa Europe Asia Australia Slide 24 Transferring Water from One Place to Another North Bay Aqueduct North Bay Aqueduct South Bay Aqueduct South Bay Aqueduct California Aqueduct CALIFORNIA NEVADA UTAH MEXICO Central Arizona Project Colorado River Aqueduct Los Angeles Aqueduct Shasta Lake Sacramento Fresno Phoenix Tucson ARIZONA Colorado River Sacramento River Sacramento River San Francisco Los Angeles San Diego Watershed transfer California Water Project Central Arizona Project James Bay Slide 25 North Bay Aqueduct South Bay Aqueduct California Aqueduct CALIFORNIA NEVADA UTAH MEXICO Central Arizona Project Colorado River Aqueduct Los Angeles Aqueduct Shasta Lake Oroville Dam and Reservoir Feather River Lake Tahoe Sacramento Fresno Hoover Dam and Reservoir (Lake Mead) Salton Sea Phoenix Tucson ARIZONA Colorado River Sacramento River San Francisco San Luis Dam and Reservoir Santa Barbara Los Angeles San Diego Slide 26 CANADA UNITED STATES NEWFOUNDLAND ATLANTIC OCEAN ONTARIO James Bay Hudson Bay Chisasibi QUEBEC New York City Chicago II I Slide 27 Dam Aqueduct or canal Upper Basin Lower Basin IDAHO WYOMING UTAH Salt Lake City Las Vegas CALIFORNIA Boulder City Los Angeles Palm Springs San Diego Mexicali Yuma Phoenix Tucson LOWER BASIN ARIZONA Grand Canyon UPPER BASIN Grand Junction Denver COLORADO NEW MEXICO Albuquerque MEXICO Lake Powell Glen Canyon Dam All-American Canal Gulf of California 0 0 100 mi. 150 km Slide 28 Trade-Offs Chinas Three Gorges Dam Advantages Disadvantages Will generate about 10% of Chinas electricity Reduces dependence on coal Reduces air pollution Reduces CO 2 emissions Reduces chances of downstream flooding for 15 million people Reduces river sitting below dam by eroded soil Increases irrigation water for cropland below dam Floods large areas of cropland and forests Displaces 1.9 million people Increases water pollution because of reduced water flow Reduces deposits of nutrient- rich sediments below dam Increases saltwater Introduced into drinking water near mouth of river because of decreased water flow Disrupts spawning and migration of some fish below dam High cost Slide 29 Tapping Groundwater Year-round use No evaporation losses Often less expensive Potential Problems! Slide 30 Problems with Using Groundwater Water table lowering Depletion Subsidence Saltwater intrusion Chemical contamination Reduced stream flows Slide 31 Water in the Ground (USGS) Slide 32 Trade-Offs Withdrawing Groundwater Advantages Disadvantages Good source of water for drinking and irrigation Available year-round Exists almost everywhere Renewable if not over- pumped or contaminated No evaporation losses Cheaper to extract than most surface waters Aquifer depletion from over- pumping Sinking of land (subsidence) when water removed Polluted aquifers unusable for decades or centuries Saltwater intrusion into drinking water supplies near coastal areas Reduced water flows into streams, lakes, estuaries, and wetlands Increased cost, energy use, and contamination from deeper wells Slide 33 Slide 34 Groundwater Overdrafts: High Moderate Minor or none Slide 35 Wells Slide 36 Major irrigation well Well contaminated with saltwater Saltwater Intrusion Normal Interface Fresh groundwater aquifer Interface Salt water Sea Level Water table Slide 37 Eastern US Aquifers Contaminated with Saltwater (USGS) Slide 38 Converting Salt Water to Fresh Water and Making it Rain Distillation desalination Reverse osmosis desalination Desalination is very expensive Cloud seeding Slide 39 Distillation desalination Reverse osmosis desalination Slide 40 Using Water More Efficiently Reduce losses due to leakage Reform water laws Improve irrigation efficiency Improving manufacturing processes Water efficient landscaping (xeriscaping) Water efficient appliances Slide 41 Too Much Water: Floods Natural phenomena Floodplain Levee Flood wall Dam Reservoir Aggravated by human activities Slide 42 Stages of Stream Development Slide 43 Ansel Adams: Snake River Slide 44 Flood Plains Slide 45 Slide 46 Slide 47 Slide 48 Solutions Groundwater Depletion Prevention Control Waste less water Subsidize water conservation Ban new wells in aquifers near surface waters Buy and retire ground- water withdrawal rights in critical areas Do not grow water- intensive crops in dry areas Reduce birth rates Raise price of water to discourage waste Tax water pumped from Wells near surface water Set and enforce minimum stream flow levels Slide 49 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 Slide 50 Solutions: Achieving a More Sustainable Water Future Efficient irrigation Water-saving technologies Improving water management Slide 51 Gravity Flow (efficiency 60% and 80% with surge valves) Water usually comes from an aqueduct system or a nearby river. Drip Irrigation (efficiency 90-95%) Above- or below-ground pipes or tubes deliver water to individual plant roots. Center Pivot (efficiency 80% with low- pressure sprinkler and 9095% with LEPA sprinkler) Water usually pumped from underground and sprayed from mobile boom with sprinklers. Slide 52 Colorado Center Pivot Irrigation Slide 53 Water Conserving Center Pivot Irrigation Slide 54 Flood Irrigation Slide 55 Furrow Irrigation Slide 56 Drip Irrigation Slide 57 Solutions Reducing Irrigation Water Waste Lining canals bring water to irrigation ditches Leveling fields with lasers Irrigating at night to reduce evaporation Using soil and satellite sensors and computer systems to monitor soil moisture and add water only when necessary Polyculture Organic Farming Growing water-efficient crops using drought- resistant and salt tolerant crops varieties Irrigating with treated urban waste water Importing water-intensive crops and meat Slide 58 Reducing Water Waste Solutions Redesign manufacturing processes Landscape yards with plants that require little water Use drip irrigation Fix water leaks Use water meters and charge for all municipal water use Use waterless composting toilets Require water conservation in water-short cities Use water-saving toilets, showerheads, and front- loading clothes washers Collect and reuse household water to irrigate lawns and non-edible plants Purify and reuse water for houses, apartments, and office buildings Slide 59 Xeriscaping in Arizona Slide 60 Slide 61 Oxygen released by vegetation Diverse ecological habitat Evapotranspiration Trees reduce soil erosion from heavy rain and wind Agricultural land Steady river flow Leaf litter improves soil fertility Tree roots stabilize soil and aid water flow Vegetation releases water slowly and reduces flooding Forested Hillside Slide 62 Tree plantation Evapotranspiration decreases Ranching accelerates soil erosion by water and wind Winds remove fragile topsoil Gullies and landslides Heavy rain leaches nutrients from soil and erodes topsoil Rapid runoff causes flooding After Deforestation Roads destabilize hillsides Agriculture land is flooded and silted up Silt from erosion blocks rivers and reservoirs and causes flooding downstream Slide 63 Not depleting aquifers Preserving ecological health of aquatic systems Preserving water quality Integrated watershed management Agreements among regions and countries sharing surface water resources Outside party mediation of water disputes between nations Marketing of water rights Raising water prices Wasting less water Decreasing government subsides for supplying water Increasing government subsides for reducing water waste Slowing population growth Solutions Sustainable Water Use Slide 64 Use water-saving toilets, showerheads, and faucet aerators Shower instead of taking baths, and take short showers. Repair water leaks. Turn off sink faucets while brushing teeth, shaving, or washing. Wash only full loads of clothes or use the lowest possible water-level setting for smaller loads. 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. Water lawns and garden in the early morning or evening. Use drip irrigation and mulch for gardens and flowerbeds. Use recycled (gray) water for watering lawns and houseplants and for washing cars. What Can You Do? Water Use and Waste