1Water Cycle, Groundwater, Water PollutionHydrologic Cyclehttp://www.mnforsustain.org/water_climate_global_water_cycle_study.htmDistribution/Cycle AnimationWater Cycle• 86% of evaporation from sea surface• 14% of atmospheric moisture from EVAPOTRANSPIRATION• 78% of precipitation on sea surface• 22% of water precipitated falls on land http://meted.com/mesoprim/mpradfog/print.htmWater CycleWater Cycle• Less that 3% of Earth’s water is on land• Over ¾ of that is in glacial ice• Most of the rest is stored as groundwater– (some groundwater is saline)Water DistributionGroundwater• Precipitation infiltrates Earth’s surface• Largest reservoir of liquid fresh water• Drinking water source for half of U.S.Water sources in Oregonhttp://www.deq.state.or.us/wq/dwp/dwp.htmGroundwaterSurface water2Groundwater• Contributes to stream flow• ‘Universal solvent’• Dissolves some rock types– Limestone (CaCO3)– Salts (NaCl, KCl)– Gypsum (CaSO4)Groundwater Source• First becomes ‘soil moisture’– Plants use it– Some evaporates directly– Some sinks down• Infiltration• ‘Groundwater’ is storedGroundwater Terms• Zone of saturation• Water table• Zone of aerationGroundwater terms diagram Groundwater Storage • Porosity of rock– Spaces between sand grains– Cracks in crystalline rock– Dissolved cavities• Permeability– Allows water to move– Interconnection of pore spaces• Stored in AQUIFER– Porous and permeable rock• Trapped by AQUITARD– Impermeable rock– Clay, shaleGroundwater StorageGroundwater Movement• Very slowly—– Small openings– High surface tension• Pressure forces water to areas of lower pressure– Hydraulic gradient– Hydraulic headGroundwater movement diagramSprings• Where water table intersects ground surface3Photo of cliff springsCarlsbad CavernsArecibo, Puerto Rico: Radio Telescope in SinkholeKarst drainage of manmade lake in MissouriKarst towering butteshttp://en.wikipedia.org/wiki/Yangshuo4Thailand Karst Towershttp://www.siue.edu/GEOGRAPHY/ONLINE/Gillespie.htmHot Springs• Water heated by hot rock (cooling magma)• Temperature increases solvent capabilities• May contain acids from magmatic waterGeysers• Special type of hot spring• Pressure of water column suppresses boiling• Heat added eventually overcomes pressure• Sudden rise of water, increase pressure release on risingOld Faithful photoOld Faithfulwebcam linkhttp://www.nps.gov/archive/yell/oldfaithfulcam.htmGeyser EruptionGeyser eruption stagesWells Wells after drawdown Artesian wells5Ogallala supported agricultureOgallala Aquifer• Exploited in Great Plains agriculture• Water table dropped• Recharge rate lowSan Joaquin Valley subsidenceNot able torecover dueto aquifercompactionWater Drophttp://www.wested.org/pblnet/exp_projects/H2O.htmlContaminated Groundwater Groundwater purificationAgriculture sources of groundwater contaminationLandfill leachate contamination Drinking Water Standards6Parts per Million• ppm• Change 1,000,000 mg to litersmg 1,000,000mg 1L 1mL 1,000L 1g 1mL 1mg 1,000g 1mg 1,000,000 =×××L 1mg 1ppm 1 =Sewage treatmentPrimary sewage treatmentSecondary sewage treatment Natural substances in water Impurities in Runoff• Atmosphere• Dissolved substances• Silt, etc.• RadonOrganic byproducts in water Contamination of Water• Micro-organisms• Decay products• Plant nutrients• Petroleum compounds•Acid• Industry• Mining Drinking water standards7Pollution Sources Raw Sewage dischargehttp://www.nwri.ca/sande/nov_dec_2002-e.htmlPlant nutrient pollutionhttp://www.na.fs.fed.us/SPFO/pubs/n_resource/riparianforests/Tab%20I.htmAgricultural Runoffhttp://www.na.fs.fed.us/SPFO/pubs/n_resource/riparianforests/Tab%20I.htmOil pollutionhttp://www.intertanko.com/tankerfacts/sizes/pollution.htmMine leachatehttp://www.ew.govt.nz/enviroinfo/hscs/contam/Water Pollutionhttp://www.jvkco.com/digidare/water.htmlWater Pollution Preventionhttp://www.jvkco.com/digidare/water.htmlDrinking water
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