Soil Porosity – High porosity  more water, that moves very slowlyMore organic matter increases porosityEast coast: Ground water flows through the river  flowing riversRivers, lakes, reservoirs all linked to ground and surface waterGW/SW removal has a variety of effectsDec stream flow/lake levelsDec water qualityInc saline concentration because not much water flowingInc levels of toxicsDon’t treat waste water for antibiotics, hormonal birth control  washed into oceanHave gotten better at conservation  less water use per capitaRapid groundwater withdrawal  subsidenceProblems with surface water: unequal distribution and seasonal variability60  85% of people now get water from public supply vs. wellWater contamination (radon)Wells dry upShift to cities vs. ruralRainfall on east coast  less water drawn for irrigation/drinkingWest coast = most withdrawalsCalifornia, then Idaho, Colorado, Arkansas withdrawals most water for irrigation than any other stateCA most productive agricultural region; 20-25% of all USChesapeake Bay: largest estuary in the USMany states drain in here  hard to regulateMaryland and Virginia feel the environmental problemsOne of the first dead zones on the planetEutrophication from all the people living in basinLots of chicken farmingHUGE decline of oyster population, which filters waterCan restore oyster population with artificial reef if get enough moneySubsurface waterGroundwater, in pore spaces of soil and rocksVadose: Unsaturated; Phreatic: SaturatedInfiltration rate decreases longer into rainfall, because soils are already saturatedCapillary flow counteracts gravitational forceSurface tension: water molecules tightly boundAdsorption: Electrostatic attraction between soil-water surfaces to prevent drainageUnconfined aquifer: No upper level boundary, rises and fallsArtesian well: Pressure has to come from a higher level, somewhere farther down the wellConfined aquifer flowing into artesian wellUpper level boundaryLA RiverProvided all the water for Los Angeles until the LA Aqueduct was constructedWould only flow in the winter months because of flooding (problem)Trying to tear out the concrete and use more natural vegetation and bottom to make it more natural, better for the environment, and an attractionDidn’t account for urbanization when the canal was constructedRunoff: After rain even, water can go on or below the surface of the streamStreamflow/Riverflow: Movement toward oceans or other bodies of water via channelDischarge measured as water volume per unit timeHydrograph: continuous measurement of water discharge or flowFlooding happens after peak rainfall because water is flowing in other areas that aren’t floodingRunoff MechanismsOverland flow: On the surfaceThroughflow: Vadose zoneGroundwater flow: infiltrates and goes under the surfaceMississippi 1992 floodAutumn: Huge rainy season; Winter: heavy snowSpring: Still extremely saturatedSummer: More rain100-200 days of floodingWorst flood of all time, based on damage done, how much rivers roseRecord flooding in 2011, New OrleansSometimes, smaller towns are sacrificed to save larger citiesEssay question: Causes of floodingSaturated soil, or close to saturated  small amt of infiltrationDeforestation: Tree cover reduces amount of rainfall on the land surfaceHigh organic soil content, and absorbs more waterUrbanization: many impervious surfaces, insufficient drainage systemsRiver channel alterations: Channels with rigid structures; downstream flow increasedLain drainage: Drainage of swamp areas for agricultural production and other usesClimate change: Extreme weather events on the rise; stream and river resilience increasesFloods: Global average is 500 mil impacted and 20k killedDisasters are on the rise in AsiaWho bears the burden?Surface and Ground Water 03/12/2013Soil Porosity – High porosity  more water, that moves very slowly-More organic matter increases porosity East coast: Ground water flows through the river  flowing rivers Rivers, lakes, reservoirs all linked to ground and surface water GW/SW removal has a variety of effects -Dec stream flow/lake levels-Dec water quality oInc saline concentration because not much water flowing -Inc levels of toxicsDon’t treat waste water for antibiotics, hormonal birth control  washed into oceanHave gotten better at conservation  less water use per capita Rapid groundwater withdrawal  subsidence Problems with surface water: unequal distribution and seasonal variability60  85% of people now get water from public supply vs. well-Water contamination (radon)-Wells dry up-Shift to cities vs. rural Rainfall on east coast  less water drawn for irrigation/drinking -West coast = most withdrawals -California, then Idaho, Colorado, Arkansas withdrawals most water for irrigation than any other state oCA most productive agricultural region; 20-25% of all US Chesapeake Bay: largest estuary in the US-Many states drain in here  hard to regulate -Maryland and Virginia feel the environmental problems -One of the first dead zones on the planetoEutrophication from all the people living in basinoLots of chicken farming oHUGE decline of oyster population, which filters water -Can restore oyster population with artificial reef if get enough money Subsurface water -Groundwater, in pore spaces of soil and rocks Vadose: Unsaturated; Phreatic: SaturatedInfiltration rate decreases longer into rainfall, because soils are alreadysaturated Capillary flow counteracts gravitational force -Surface tension: water molecules tightly bound -Adsorption: Electrostatic attraction between soil-water surfaces to prevent drainage Unconfined aquifer: No upper level boundary, rises and fallsArtesian well: Pressure has to come from a higher level, somewhere farther down the well -Confined aquifer flowing into artesian well-Upper level boundary LA River-Provided all the water for Los Angeles until the LA Aqueduct was constructed -Would only flow in the winter months because of flooding (problem)-Trying to tear out the concrete and use more natural vegetation andbottom to make it more natural, better for the environment, and an attraction -Didn’t account for urbanization when the canal was constructed Runoff: After rain even, water can go on or below the surface of the stream Streamflow/Riverflow: Movement toward oceans or other bodies of water via