Freshwater Resources

Freshwater ResourcesFreshwater Systems97.5% of Earth is water, only 2.5% is freshwaterFreshwater water that is relatively pure, with few dissolved saltsMost freshwater is locked up in polar icecaps and icebergs, and underground aquifersOnly 1 part in 10,000 is available for human use

Hydrologic CycleWater carries nutrients and sediments to the oceans from riversDistributes nutrients and sediments in the ocean through currentsHydrologic cycle summarizes how water in its three forms flow through our environmentEvaporation conversion of liquid water into a gaseous stateWarm temperatures speed up evaporationAreas of less growth will lose more waterTranspiration release of water vapor from plants through their leavesStrong winds and/or higher temperatures speed up transpiration

Precipitation- water vapor condenses and falls as rain or snow from Earths atmospherePlants will use water this wayMost is lost as runoff into lakes, ponds, rivers, oceans, and streamsGroundwater water under the surface that gets recharged by precipitation or surface water Water soaks through into aquifersWater table the upper limit of groundwater held in an aquifer, aquifer

7Human Impacts on the Hydrologic Cycle- damming rivers creating reservoirs -destroys habitat by flooding land previously not underwater

Impacts cont

Increase evaporation by clearing landsIncrease surface water and runoffBy eliminating farm lands and forest, we reduce the amount of vegetation, reducing transpirationOverdrawing groundwater for use depleting our water resource

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How we use waterHousehold use, Agricultural, and IndustryNations with dry climates use more water for agriculture.Heavily industrialized nations use more water.Globally, we use 70% of freshwater for agriculture, 20% for industry, and residential/municipal accounts for 10%.

Types of UseConsumptive Use we remove water from an aquifer or surface water and do not return itNonconsumptive Use water does not remove, or only temporarily removes water from an aquifer or surface water bodyExample: Dam

Surface WaterSurface water water found on Earths SurfaceSources include rainfall, melting snow, glaciers, and ice capsSurface water moves from these sources to bodies of surface water as runoffRunoff water that flows over land that is not absorbed into the groundRiver system network of connected streams and rivers that form as water moves downhillWater moves in the following progressionShallow groves in the Earths crust stream large stream small river (tributaries) large river large body of water

River Systems of NJMullica River SystemWatersheds includes all of the land area that supplies water to a particular river systemWatershed structure there are 9 major watersheds that make up the USEach is made up of many different watershedsManaging Watersheds upstream pollution will have negative effects on the downstream watershedRequires cooperation of all individuals who live within the watershedUsing Surface WaterDiverting waterWater diversion the process of moving from its source to places where humans use itDam an obstruction placed in a river or stream to block its flowCreates an artificial reservoir (lakes that store water for human use)There are 80,000 dams in use in the US.Canal water diverted from a river to irrigate farmlands that are not near any surface water resourcesCosts and Benefits of DamsCostsBenefitsHabitat alterationFisheries declinePopulation displacementSediment captureLoss of fertile farmlandRisk of failureLost recreational opportunitiesClean power generationHydroelectricCrop irrigationFlood controlShippingNew recreational opportunitiesSurface water depletionDrought and overuse contribute most to depletion of surface waterDried-up rivers too much water is diverted upstream, therefore, eliminating water flow downstream in heavily used areasThe Aral Sea two rivers were diverted to irrigate thirsty cotton fieldsThe rivers flood the Aral Sea, but since the diversion, the sea has shrunk to 10% of its original size.60,000 fishing jobs were lost.Using GroundwaterGroundwater is being used primarily for irrigation faster than it can be replenished.Agricultural Uses 26% of the freshwater used in the US comes from groundwater; of that 68% is used for irrigationMost water is lost to run-off and evaporationToo much water can be detrimental.Waterlogging the soil becomes saturated with water to the point that oxygen no longer gets inSalinization buildup of salts in the surface layers of soil.

Groundwater Mining18% of groundwater goes to public use for drinking, washing, etc..Groundwater mining using groundwater faster than it can be replacedTurn water into a nonrenewable resourceLowers the amount of water in aquifersDrops the water tables causes land over top to become weak, not being able to support itSinkholes areas where the ground gives way swallowing up everything on the surface

Groundwater DepletionAs mining increases, the volume of water in the aquifer decreasesAs groundwater leaves, salt water travels through cracks in the stone contaminating the remaining freshwater with high salt concentrations.Causes streets to buckle, buildings that flood, pipes to break, building to lean.

http://edro.wordpress.com/2008/02/

Solutions to Freshwater DepeletionSolutions that increase supplyDesalination the technology of removing salt from saltwater to make freshwaterMethods One method: boiling seawater to produce water vapor, then condense (cool) the vapor in order to collect the waterReverse osmosis forces water through artificial membranes to filter out salts Very expensiveRequires a lot of Energy

Solutions that Reduce DemandAgricultural SolutionsDrip irrigation systemLess water lost to evaporationClimate-appropriate cropsLess water needed to growIndustrial SolutionsCompanies have contracts with municipalities for certain amounts of water; recycle wastewaterPersonal SolutionsWatering at nightChose outdoor plants adapted to the conditionsCalled xeriscapingLow flow toilets, showers, sinksFixing leaky pipes

Water PollutionTypes of Water PollutionPoint-Source Pollution pollution that comes from a distinct locations such as a factory or sewer pipeNonpoint-Source Pollution pollution that comes from many places over a large areaWatershed pollution carries all runoff to large bodies of water

Nutrient Pollution areas of water that have a high nutrient content but low oxygen content are called eutrophicEutrophication natural process of the build up of nutrients in a body of waterFreshwater usually has a build-up of phosphorusHow it happens;As phosphorus levels rise, so does the population of algae and aquatic plantsMore growth means more death; which leads to decomposition of dead organic materialDecomposition requires oxygen which lowers the oxygen levels in the waterEnd result is a high nutrient low oxygen containing body of water..Eutrophic

Cultural Eutrophication nutrient pollution by humans, also called artificial eutrophicationUsually occurs because of non-point source pollution from fertilizers and detergents carried in runoffCauses algal blooms explosions in algal populations due to the increase in phosphorusMay cover the entire surface of a body of water; blocks sunlight for photosynthesis, decomposition increases, oxygen levels decrease

Toxic-Chemical Pollution organic or inorganic pollutants in the freshwaterPetroleum (plastics, mercury, arsenic, lead)Sediment Pollution more sediment being deposited down river causing photosynthesis rates to change, causing food webs to collapseIs a result of erosion; mostly man-made.Thermal Pollution the warmer water is, the less oxygen it can hold (increased molecular motion)Industrial processes use water to cool down machineryWhen the water is returned, it is warmer than when it startedRemoval of trees; addition of treesBiological Pollution disease causing pathogens make their way into soil and waterHuman or animal wasteCauses more health problems than any other pollution typeAccess to clean water will reduce the death toll due to contaminated drinking waterMost deaths occur in South Asia and sub-Saharan Africa in young childrenGroundwater PollutionSourcesHuman intervention is the reason why groundwater pollution is so widespread.Chemicals from fertilizers and pesticides leach down (soak) into aquifers.Leaky wells and faulty storage tanks from industry also add to this problem.

Cleaning up Groundwater Natural processes do filter away pollutants, however, it takes many years.DDT is still found in underground water although its use was banned in 1972.Decomposition is slower in groundwater than in surface water.Why? Less microbes, does not move as much, takes a long time to rechargeHow can groundwater be cleaned up?Locate and repair gasoline tanks, sewage tanks, oil tanks, etc..

Ocean water PollutionOil PollutionMost oils spillage comes from small nonpoint-sources such as small boats, runoff from human activities on land.Oil coats and kills marine organisms, shattering food webs.Oil Pollution Act set aside $1 billion for prevention and cleanupMandates that oil tankers have a double hull to prevent oil leaks

http://www.youtube.com/watch?v=oILB2LwfKYoMercury PollutionMercury is a toxic heavy metal that collects in the tissues of marine organisms.Makes its way up the food chain by biological magnification.Biological Magnification of DDT in a Food Chain

Food Chain Concentration of DDT in A Long Island Marsh sprayed for Mosquito Control 1967 ppmWater.00005Plankton.04Silverside Minnow.23Sheephead Minnow.94Pickerel1.23Needlefish2.07Heron3.57Tern3.91Osprey13.8Merganser22.8Cormorant26.4Nutrient Pollution in the OceanNitrogen effects the oceans in the same way phosphorus effects freshwater systems.Red Tides algal blooms in the ocean cause red pigments to be produced and released into the food chain.Pigments may cause illness and death among zooplankton, fish, marine mammals, birds, and humans.The only way to stop this is to reduce nutrient runoff from land.

Controlling Water PollutionThe Clean Water Act of 1977Made it illegal to release pollution from point source without a permitSet standards for pollution levels in surface water and industrial wastewaterWater TreatmentDrinking water treatment EPA set standards for 80 possible contaminantsWastewater Treatment water from homes, industry, farming

Water Treatment Facility

Septic System

Septic systems are the most popular method of wastewater disposal in rural areas of the U.S.