~2.5% of the Water on Earth is: Freshwater. ~20% of global freshwater is in: the Great Lakes. ~50% of people have: well/septic systems. Global Water Resources and the Hydrogeologic Cycle Key Concepts -The physical properties of water -Availability of fresh water -Methods of increasing freshwater supplies. -Using water more efficiently -Hydrogeologic cycle?Surface Water and -Groundwater?Terms and behavior Water Resources?Why is water so important? -Required for life?no plant or animal can survive without it. -Fresh, clean, portable water needed by people for: -cleaning -drinking, cooking -Agriculture?production and processing of food and feed -Industrial processes -Waste disposal Water Resources -Renewable? or are they? Water cycles but there is no new water on the planet. -Rate ?used? vs. rate replenished -Quality and Distribution?Key issues. Properties of Water -Special properties makes water unique: -Surface tension: Can form droplets; clings to soil, etc. -Good Solvent: -Many elements and compounds dissolve -Facilitates biogeochemical cycling -Important in many physiological functions -High heat capacity: -Transfers heat around Earth -Moderate climate -Excellent coolant -Expands when it freezes: ice floats -Water is densest at: 4 degrees Celsius -Exists as solid, liquid gas on Earth?s surface: -ice, liquid water, water vapor -Liquid over a broad temperature range (0 to 100 C) -Water is the lifeblood of the Biosphere! Global Warming and Water Resources -Increases rates of evaporation -Desiccation of some surface waters -Change in precipitation patterns -Storms will intensify?ex. 2005 Hurricanes, 2009 Typhoons, crazy 2010 winter storms. -Sea levels will rise?Flooding on coasts -Others that are unknown Flow of Water Between Compartments: -Evaporation/precipitation -Infiltration/Transpiration/runoff (water laterally moving across the surface of the Earth) -Groundwater flow/stream flow -The Water Cycle (hydrologic cycle) Groundwater Aquifer: A groundwater supply or reservoir -A layer of rock or soil that contains accessible water in its pores or spaces -To serve as a water supply, a layer must: -Be able to store water -Be able to yield water (so we can use it) Aquifer Characteristics -Porosity: Proportion of void space in a layer. -Needed to store water. -Permeability: How easily water flows through a layer -Needed to yield water to wells. Groundwater -Water Table: Surface of the saturated zone. -Position fluctuates with stored H2O. -Recharge: Add water to an aquifer (flow in) -Increases Storage -Only possible if the ground is permeable Hydrologic Cycle From: HYPERLINK "http://cals.arizona.edu/extension/riparian/images/ch3_hydro-cycle.jpg" http://cals.arizona.edu/extension/riparian/images/ch3_hydro-cycle.jpg Movement of Groundwater From: HYPERLINK "http://www.bgs.ac.uk/science/landUseAndDevelopment/images/sustainable_soils/98002816.JPG" http://www.bgs.ac.uk/science/landUseAndDevelopment/images/sustainable_soils/98002816.JPG Groundwater -Discharge: Loss of water from an aquifer (flow out) -Springs, streams, wells -Balance: Balance between recharge and discharge is needed to maintain a stable water supply (renewable resource). Groundwater Problems -Overdraft: Use faster than recharge -Withdraw vs. consumption -Example: Ogallala Aquifer -Where else do we use the term ?overdraft??? Banking. -Contamination -?out of sight, out of mind? -Because groundwater is underground, contamination is hard to locate and track. -Aquifer vulnerability -Examples: -Septic pollution -Landfill pollution -Saltwater incursion From: HYPERLINK "http://www.kgs.ku.edu/HighPlains/2000-29B/ogdec4.gif" http://www.kgs.ku.edu/HighPlains/2000-29B/ogdec4.gif From: HYPERLINK "http://www.qwestinspect.com/images/septic2.jpg" http://www.qwestinspect.com/images/septic2.jpg Saltwater Incursion From: HYPERLINK "http://web.arc.losrios.edu/~borougt/SaltWaterIncursion.gif" http://web.arc.losrios.edu/~borougt/SaltWaterIncursion.gif Water Resource Issues -Insufficient Water -Insufficient water for crops: -famine, desiccation, desertification?Northern Africa -Water ?wars? -Western U.S. depletion of supplies due to: population growth, cattle, crops -Middle East: arid climate, little water, could lead to real war. Gallon of Gas: $2.79 Bottle of water: $1-1.19 16 oz/pt x 8 $8-$9.80 per gallon for water. From: HYPERLINK "http://sites.google.com/site/littleblueriverwatershed/_/rsrc/1236708436239/Home/whatisawatershed/MississippiRiverBasin.jpg" http://sites.google.com/site/littleblueriverwatershed/_/rsrc/1236708436239/Home/whatisawatershed/MississippiRiverBasin.jpg Water Resource Issues -Insufficient clean water -Water-borne diseases. Cholera. -WHO: 80% 3rd world diseases -Loss of habitats and ecosystems -Water diverted for human use leaves less for natural ecosystems. -Florida everglades From: HYPERLINK "http://www.stumbleupon.com/su/35kOfq/kuvation.com/kuvei/facts_about_bottled_water.jpg" http://www.stumbleupon.com/su/35kOfq/kuvation.com/kuvei/facts_about_bottled_water.jpg -Most of the oxygen on Earth comes from: algae. -Most algae is in: the ocean.
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