Transcript Ch 14
Water Resources G. Tyler Miller’s Living in the Environment 13th Edition Chapter 14 Dr. Richard Clements Chattanooga State Technical Community College Key Concepts The physical properties of water Availability of fresh water Methods of increasing freshwater supplies Using water more efficiently Problems associated with flooding Water’s Unique Properties Hydrogen bonding Liquid over wide temperature range Changes temperature slowly High heat of evaporation Great dissolving power pH Adhesion and cohesion Expands when it freezes Supply of Water Resources Freshwater Readily accessible freshwater Groundwater 0.592% Biota 0.0001% Lakes 0.0007% Ice caps and glaciers 0.592% 0.014% Fig. 14-2 p. 314 Soil moisture 0.0005% Rivers 0.0001% Atmospheric water vapor 0.0001% Surface Water Surface runoff Reliable runoff Watershed Drainage basin Ground Water Fig. 14-3 p. 315 Flowing artesian well Precipitation Well requiring a pump Evaporation and transpiration Evaporation Confined Recharge Area Runoff Aquifer Infiltration Stream Water table Lake Infiltration Unconfined aquifer Less permeable material such as clay Confined aquifer Confirming permeable rock layer Use of Water Resources Humans use about 50% of reliable runoff United States Agriculture Industry Power cooling 38% Domestic Agriculture 38% Power plants Fig. 14-5 p. 316 Industry 11% Public 10% Too Little Water Dry climate Drought Dessication Acute shortage Water stress Fig. 14-7 p. 317 Adequate supply Shortage Metropolitan regions with population greater than 1 million Using Dams and Reservoirs to Supply More Water Flooded land destroys forests or cropland and displaces people Large losses of water through evaporation Downstream cropland and estuaries are deprived of nutrient-rich silt Downstream flooding is reduced Reservoir is useful for recreation and fishing Can produce cheap electricity (hydropower) Fig. 14-9 p. 319 Migration and spawning of some fish are disrupted Provides water for year-round irrigation of cropland Transferring Water from One Place to Another Watershed transfer CALIFORNIA NEVADA Sacramento River California Water Project North Bay Aqueduct Shasta Lake Sacramento San Francisco South Bay Aqueduct Central Arizona Project Fresno Los Angeles Aqueduct California Aqueduct James Bay UTAH Los Angeles Colorado River ARIZONA Central Arizona Project Phoenix San Diego Colorado River Aqueduct Tucson MEXICO Fig. 14-13 p. 323 Tapping Groundwater Year-round use No evaporation losses Often less expensive Potential Problems! Problems with Using Groundwater Water table lowering (See Fig. 14-15 p. 326) Depletion (See Fig. 14-16 p. 326) Subsidence (See Fig. 14-16 p. 326) Saltwater intrusion (See Fig. 14-17 p. 328) Chemical contamination Reduced stream flows See Case Study p. 327 Converting Salt Water to Fresh Water and Making it Rain Distillation desalination Reverse osmosis desalination Desalination is very expensive Cloud seeding Using Water More Efficiently Reduce losses due to leakage Reform water laws Improve irrigation efficiency (Fig. 14-18 p. 330) Improving manufacturing processes Water efficient landscaping Water efficient appliances Too Much Water: Floods Natural phenomena Aggravated by human activities Renew and replenish Reservoir Dam Levee Flood wall Floodplain Fig. 14-22 p. 332 Solutions: Achieving a More Sustainable Water Future Efficient irrigation Water-saving technologies Improving water management See Fig. 14-25 p. 336