Water ResourcesHydrologic CycleSlide 3Distribution of Water (from your text book-based on 1972 data)Distribution of Water http://ga.water.usgs.gov/edu/waterdistribution.html (1997 data)Slide 6Heat Capacity of WaterPrecipitation/Evaporation patternsSlide 9Slide 10World water resourcesEvaporation (mean annual U.S.)http://ga.water.usgs.gov/edu/watercycleevapotranspiration.htmlMean Annual EvapotranspirationWhen ppt >>> e/tFreshwater ReservoirsGroundwaterWater TableWhat is an aquifer?Slide 20Surface Water/Floods/Flood ControlSlide 22Stream Discharge HydrographWhen does flooding occur?What do we do to minimize flooding?Dams: proDams: conSome DamsGlen Canyon DamHoover DamThree Gorges DamLeveesChannelizationDrawbacksKissimmee river in FloridaDrawbacks of ChannelizationSlide 37Water Resources•1. Hydrologic Cycle and Water Reservoirs•2. Floods and Flood Control•3. Use of Water•4. Water Composition•5. Water ProblemsHydrologic Cycle•Plop–Plop plopDistribution of Water(from your text book-based on 1972 data)Type Location Volume (l) PercentSurface Lakes 1.25 x 10170.009Saline lakes/seas 1.04 x 10170.008Streams 1.00 x 10150.0001Subsurface Vadose 6.7 x 10160.005Groundwater (to 750 m) 4.17x 10180.31Groundwater (below 750m) 4.17x 10180.31Other Reservoirs Icecaps, glaciers 2.9 x 10192.15Atmosphere 1.3 x 10160.001Oceans 1.32 x 102197.2Distribution of Waterhttp://ga.water.usgs.gov/edu/waterdistribution.html (1997 data)Source Volume (km3) % Fresh % TotalOceans 1338 x 10696.5Ice caps/glaciers 24 x 10668.7 1.74Groundwater 23.4 x 106 Fresh 10.53 x 10630.1 0.76 Saline 12.87 x 1060.94Soil Moisture .0165 x 1060.05 0.001Permafrost 0.3 x 1060.86 0.022Lakes 0.1764 x 1060.013 Fresh 0.091 x 1060.26 0.007 Saline 0.0854 x 1060.006Atmosphere 0.0129 x 1060.04 0.001Swamp Water 0.0115 x 1060.03 0.0008Rivers 0.00212 x 1060.006 0.0002Biological Water 0.00112 x 1060.003 0.0001Bibliographical Acknowledgment referenced publication for content development Peixoto and Kettani, 1973 The Control of the Water Cycle Scientific American - Vol. 228 - pp. 46-6Heat Capacity of Water•This means that water has the ability to absorb and hold heat with a minimal change in temperature•Why?•When water evaporates it takes 540 cal/gm. This means that evaporation creates a cooling effect.•Ice going to water releases 80 cal/gm, thus releasing heatPrecipitation/Evaporation patterns•http://weather.msfc.nasa.gov/GOES/World water resourceshttp://www.worldmapper.org/Evaporation (mean annual U.S.)http://geochange.er.usgs.gov/sw/changes/natural/et/http://ga.water.usgs.gov/edu/watercycleevapotranspiration.htmlEvapotranspirationMean Annual EvapotranspirationWhen ppt >>> e/t•Then we get rivers and streams•Eastern NA—water surplus•Western US—water deficiency•Plays a role in population density in U.S. and CanadaFreshwater Reservoirs•Rivers and Streams•Lakes•Icecaps•GroundwaterGroundwater•Much greater in volume than either lakes or streams•Non-renewable in our lifetimeWater Table•Surface below which pores and fractures of rocks and overburden are water filledWhat is an aquifer?•Geologic formation that possesses porosity and permeabilityWater Resources•1. Hydrologic Cycle and Water Reservoirs•2. Floods and Flood Control•3. Use of Water•4. Water Composition•5. Water ProblemsSurface Water/Floods/Flood Control•Surface water is water that flows off the land in streams and rivers•What is it dependent upon??•Amount of rainfall•Slope and Length of drainage basin•Rock and soil type of drainage basin•Vegetation•Extent of impermeable areasStream Discharge HydrographWhen does flooding occur?•When surface run-of exceeds a normal stream channel’s capacity and water spreads out onto the flood plain•Is this a problem?What do we do to minimize flooding?•1. build dams•2. build levees•3. create channels (channelization)•4. Moveable dams—ThamesDams: pro•1. Do help with flood control•2. Supply electricity•3. Provide recreation•4. Sources of water for irrigation•5. Increases groundwater•Does anyone see some inconsistency here?Dams: con•1. Sediment catchment•2. Increased evaporation•3. Loss of land•4. Interruption of river transport and fish migration•5. Environmental alterationSome Dams•Aswan High DamGlen Canyon DamHoover DamThree Gorges DamLeveesChannelization•Replacement of a meandering stream by a deeper, straighter channelDrawbacks•Transfer of flooding•Flood plain doesn’t get new sedimentKissimmee river in FloridaDrawbacks of Channelization•Increased erosion•Transfer of flooding downstream•Reduced natural filtering of water and drainage basin•Loss of wetlands•Reduction in available water for general use•Less evapotranspiration•Less infiltration•Lower ground water levels•Larger variations in flow rates•Reduction in