ENV 101 -- Lecture: -- March 1, 2010 Guest speakers: Pat Donovan (Donovanp@michigan.gov) Sandee Sinclair (Sinclairs@michigan.gov) Crater Lake, Oregon http://www.dustydavis.com/blogimages/crater_lake_large.jpg ~2.5 % - Freshwater ~20% Percent of global freshwater in our Great Lakes ~50% Percentage of people on well/septic systems 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 ground water (terms and behavior) Sketch, diagram and label Hydrogeologic cycle ? last question on exam http://www.omsolar.net/en/system_z/img/watercycle.jpg Water resources ? why is water so important? Required for life ? no plant or animal can survive without it Fresh, clean, potable water needed by people for: Cleaning, drinking, cooking, agriculture (production and processing of food and feed), industrial processes, waste disposal Renewable ? or are they? Water cycles but there is no new water on the planet Rate ?used? vs. rate replenished (by Hydrogeologic cycle) Quality and distribution are key issues Properties of water: Special properties make water unique (H2O) http://www.chem.ufl.edu/~itl/2045/react/0916.jpg Surface tension Can form droplets; clings to soil; etc Important for water to be able to move through life systems Good solvent Many elements and compounds dissolve Facilitates biogeochemical cycling Important in many physiological functions High heat capacity Transfers heat around Earth Moderates climates Excellent coolant Expands when it freezes: ice floats Most dense at 4ºC Allows for fish to live under ice when tops of bodies of water freeze Otherwise, lakes would freeze from bottom up and life systems in water would be concentrated at the top; unstable living system Exists as solid, liquid, gas on Earth?s surface Ice, liquid water, water vapor Liquid over a broad temperature range (0-100º C) Range can be extended through other chemicals/elements Water is the lifeblood of the biosphere! Earth?s water supply http://www.urbanrivers.org/web_images/water_pie.jpg Global warming and water resources Increased rates of evaporation and sublimation (snow on ground in warmer temperatures goes directly from solid to gas) Desiccation of some surface waters Average increase of summer temperatures: 1º C Change in precipitation patterns Storms will intensify ? examples: 2005 hurricanes, 2009 typhoons, crazy 2010 winter storms Systems with more energy and water in the atmosphere mean greater frequency of high energy intense storms Sea levels will rise ? flooding on coasts Others that are unknown (agricultural systems not being able to function if it rains in the winter instead of the spring, etc) Flow of water between compartments Evaporation and precipitation Evaporation: change of water from liquid to gas Precipitation/condensation: change of water from gas to liquid Infiltration, transpiration, and runoff Infiltration ? water permeates the ground after a rain fall Transpiration ? water moves up plant roots, in put into vegetative cells, and into the air Runoff ? lateral movement of water across the ground Groundwater flow and stream flow Groundwater flow: very slow flow of water underground; helps to ensure base flow in streams when there is no precipitation http://www.atmos.uiuc.edu/earths_atmosphere/images/water_cycle/hydrologic_cycle2.jpg http://www.buffer.forestry.iastate.edu/Photogallery/illustrations/Images/Hydrologic-Cycle.jpg Groundwater Aquifer: A groundwater supply or reservoir (water-bearing sand or gravel, or hard rocks, that have sufficient pore space to hold water A layer of rock or soil that contains accessible water in its pore 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) (permeable layers) Aquifer characteristics: Porosity: Proportion of void spaces 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 http://www.co.pepin.wi.us/Groundwater%20Website/New%20Folder/perch2.jpg http://web.arc.losrios.edu/~borougt/WaterMovement.gif http://www.fayettecountygroundwater.com/images/cone_of_depression.jpg Groundwater Discharge: Loss of water from 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 Withdrawal v. consumption Example: Ogallala Aquifer Where else do we use the term overdraft? Banking ? writing checks/charging money to accounts that don?t have enough of a balance to cover the charges Ogallala Aquifer http://irf-info.com/wp-content/uploads/2009/05/ogallala_usgs.gif http://www.choicesmagazine.org/2003-1/2003-1-04-1a.jpg Groundwater problems 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 (pumping too much water out of aquifers and drawing in salt water) Septic Systems http://www.qwestinspect.com/images/septic2.jpg Septic Pollution and Landfill Pollution http://earthsci.org/education/teacher/basicgeol/solid_waste/sanitary-landfill.jpg Saltwater incursion 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 US depletion of supplies due to: Population growth, cattle, crops Middle East: arid climate, little water, could lead to real water http://www.imf.org/external/pubs/ft/fandd/2001/09/images/map.gif Iraq ? ?Land of Water? http://www.cgiar.org/enews/june2007/images_06_07/story12c.gif Comparative water use ? US v. China http://lh5.ggpht.com/_MO1iIC_MYgk/Sx0Fhn55J9I/AAAAAAAAC6s/3C3V2j0W954/China%20water%20supply%20and%20demand%20gap.JPG http://www.treehugger.com/water-withdrawal-map-usa2.png Water Deficit regions in US http://1.bp.blogspot.com/_C5lyb6Dp3LU/R1PwvZA20DI/AAAAAAAACC4/mNhck7NkjSw/s1600-R/Picture+39.png http://imgs.sfgate.com/blogs/images/sfgate/gleick/2009/12/02/total_dm_091124500x386.jpg Water sheds in the US: http://www.watersheds.org/places/extension/images/map_missbasins.gif http://whyfiles.org/282dead_zone/images/dzmap1.gif http://gcvconservation.files.wordpress.com/2009/12/dead-zones-in-the-chesapeake-bay.jpg Water Resource Issues Insufficient clean water Water-borne diseases like cholera that are increasing around the world WHO: 80% 3rd world diseases Loss of habitats and ecosystems Water diverted for human use leaves less for natural ecosystems Florida Everglades Bottled Water v. Tap Water Go to: http://www.onlineeducation.net/bottled_water/
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