Water and Water Pollution

Water and Water Pollution

اسلاید 1: Water and Water Pollution

اسلاید 2: Case Study: Water ConflictsWater shortages in the Middle EastNile RiverJordan BasinTigris and Euphrates Rivers

اسلاید 3: Three Major River Basins in the Middle East

اسلاید 4: Will We Have Enough Water?We are using available freshwater unsustainablywasting it polluting it charging too little for this irreplaceable natural resource.One of every six people do not have sufficient access to clean water, and this situation will almost certainly get worse.

اسلاید 5: Importance and Availability of WaterWhy is water so important?Earth as a watery world – 71%Freshwater availability – 0.024%Poorly managed resourceHydrologic cycleWater pollution

اسلاید 6: Confining impermeable rock layerLess permeable material such as clayStreamWellrequiringa pumpLakeUnconfined aquiferFlowingartesian wellRunoffConfinedRechargeAreaWatertableConfined aquiferInfiltrationEvaporationEvaporation and transpirationInfiltrationUnconfined Aquifer Recharge AreaRecharge Unconfined AquiferPrecipitation

اسلاید 7: GroundwaterZone of saturationWater tableAquifersNatural recharge

اسلاید 8: Surface WaterSurface runoffWatershed (drainage) basinReliable runoff – 1/3 of totalRunoff useDomestic – 10%Agriculture – 70%Industrial use – 20%

اسلاید 9: Case Study: Freshwater Resources in the United StatesUneven distributionContaminationEastern U.S.Western U.S.Groundwater withdrawal – 50%

اسلاید 10: Stepped ArtAverage annual precipitation (centimeters)Less than 4141-8181-122More than 122Acute shortageShortageAdequate supplyMetropolitan regions with population greater than 1 million

اسلاید 11: Water Hot Spots in Western States

اسلاید 12: Freshwater ShortagesCauses of water scarcityDry climateToo many people1 of 6 people – no regular access to clean waterOver one billion have no access to improved drinking water According to the U.N. childrens agency UNICEF, polluted water and lack of basic sanitation claim the lives of over 1.5 million children every year, mostly from water-borne diseases.

اسلاید 13: While most people living in Western Europe can access safe water, only 50% of people living in Central Africa can do this. The largest population without access to safe tap water is in China (25%)waterwiki.net/index.php/Unsafe_Water

اسلاید 14: Stress on World’s River Basins

اسلاید 15: How Can We Increase Water Supplies? Groundwater used to supply cities and grow food is being pumped from aquifers in some areas faster than it is renewed by precipitation.Using dams, reservoirs, and transport systems to transfer water to arid regions has increased water supplies in those areas, but has disrupted ecosystems and displaced people.

اسلاید 16: How Can We Increase Water Supplies? We can convert salty ocean water to freshwater, but the cost is high, and the resulting salty brine must be disposed of without harming aquatic or terrestrial ecosystems.

اسلاید 17: Increasing Freshwater SuppliesWithdrawing groundwaterDams and reservoirsTransporting surface waterDesalinationWater conservationBetter use of natural hydrologic cycle

اسلاید 18: Aquifer Depletion from Groundwater Overdraft in the United States

اسلاید 19: Saltwater Intrusion into Coastal Water Wells

اسلاید 20: Trade-offs of Large Dams and Reservoirs

اسلاید 21: California Water Project and Central Arizona Project

اسلاید 22: Aral Sea DisasterLarge-scale water transfers in dry central AsiaSalinityWetland destruction and wildlifeFish extinctions and fishing

اسلاید 23: Aral Sea DisasterWind-blown saltWater pollutionClimatic changesRestoration efforts

اسلاید 24: Shrinking Aral Sea

اسلاید 25: Removing Salt from SeawaterDesalinationDistillationReverse osmosis15,000 plants in 125 countries

اسلاید 26: Major Problems with DesalinationHigh costDeath of marine organismsLarge quantity of brine wastesFuture economics

اسلاید 27: Ashkelon Plant supplies 15%of Israel’s Householdswater needs-Largest plant in 2005

اسلاید 28: How Can We Use Water More Sustainably?We can use water more sustainably by cutting water waste, raising water prices, slowing population growth, and protecting aquifers, forests, and other ecosystems that store and release water.

اسلاید 29: Reducing Water Waste (1)Benefits of water conservationWorldwide – 65-70% loss Evaporation, leaksWater prices, government subsides, waste

اسلاید 30: Reducing Water Waste (2)Improve irrigation efficiencyImprove collection efficiencyUse less in homes and businesses

اسلاید 31: Major Irrigation Systems

اسلاید 32: Reducing Irrigation Water Waste

اسلاید 33: Reducing Water Waste

اسلاید 34: Sustainable Water Use

اسلاید 35: What Can You Do?

اسلاید 36: How Can We Reduce the Threat of Flooding?We can improve flood control by protecting more wetlands and natural vegetation in watersheds and by not building in areas subject to frequent flooding.

اسلاید 37: Benefits of Floodplains (1)Highly productive wetlandsProvide natural flood and erosion controlMaintain high water qualityRecharge groundwater

اسلاید 38: Benefits of Floodplains (2)Fertile soilsNearby rivers for use and recreationFlatlands for urbanization and farming

اسلاید 39: Dangers of Floodplains and FloodsDeadly and destructiveHuman activities worsen floodsFailing dams and water diversionHurricane Katrina and the Gulf CoastRemoval of coastal wetlands

اسلاید 40: Before and During a Flood in St. Louis, Missouri

اسلاید 41: Case Study: Floodplains of BangladeshDense populationLocated on coastal floodplainModerate floods maintain fertile soilIncrease frequency of large floodsDevelopment in the Himalayan foothillsDestruction of coastal wetlands

اسلاید 42: Hillside Before and After Deforestation

اسلاید 43: Reducing Flood Damage

اسلاید 44: How Can We Best Deal with Water Pollution? (1)Streams can cleanse themselves of many pollutants if we do not overload them.Preventing water pollution usually works better and costs less than trying to clean it up.

اسلاید 45: How Can We Best Deal with Water Pollution? (2)Reducing water pollution requires preventing it, working with nature in treating sewage, cutting resource use and waste, reducing poverty, and slowing population growth.

اسلاید 46: Water Pollution SourcesWater pollutionPoint sourcesDischarge at specific locationsEasier to identify, monitor, regulateNonpoint sourcesRunoff of chemicals and sedimentAgricultureControl is difficult and expensive

اسلاید 47: Major Water Pollutants and Their Sources

اسلاید 48: Pollution in Streams

اسلاید 49: Lake Pollution (1)Dilution less effective than with streamsStratificationLow flowLakes are more vulnerable than streamsEutrophication – natural aging processOligotrophic

اسلاید 50: Oligotrophic and Eutrophic Lakes

اسلاید 51: Groundwater Pollution (1)SourcesSlow flow, dilution, dispersionLow dissolved oxygenFewer bacteriaCooler temperatures

اسلاید 52: Groundwater Pollution (2)Longtime scale for natural cleansingDegradable wastes – organic matterSlowly degradable wastes – DDTNondegradable wastes – lead, arsenic, fluoride

اسلاید 53: Sources of Groundwater Pollution

اسلاید 54: Extent of Groundwater PollutionGlobal scale – not much knownMonitoring is very expensiveUnderground fuel tank leakageMTBEArsenicProtecting groundwater – prevention is best!

اسلاید 55: Preventing and Cleaning Up Groundwater Pollution

اسلاید 56: Ocean PollutionCoastal areas – highly productive ecosystemsOccupied by 40% of populationTwice that population by 2050About 80% marine pollution originates on landDeep ocean watersSome capacity to dilute, disperse, degrade pollutantsOcean dumping controversiesAssimilative capacity?

اسلاید 57: Coastal Water Pollution

اسلاید 58: Science Focus: Oxygen Depletion in the Northern Gulf of Mexico

اسلاید 59: Oil Pollution in OceansCrude and refined petroleumTanker accidents – Exxon ValdezUrban and industrial runoff

اسلاید 60: Effects of Oil Pollution on Ocean EcosystemsVolatile organic hydrocarbonsKill larvaeDestroys natural insulation and buoyancyHeavy oilSinks and kills bottom organismsCoral reefs die

اسلاید 61: Oil Cleanup MethodsCurrent methods recover no more than 15%Prevention is most effective methodControl runoffDouble haul tankers

اسلاید 62: Preventing and Cleaning Up Pollution in Coastal Waters

اسلاید 63: Preventing Nonpoint Source Pollution (1)Mostly agricultural wasteUse vegetation to reduce soil erosionReduce fertilizer use

اسلاید 64: Preventing Nonpoint Source Pollution (2)Use plant buffer zones around fields and animal feedlotsKeep feedlots away from slopes, surface water and flood zonesIntegrated pest management

اسلاید 65: Laws for Reducing Point Source PollutionClean Water ActWater Quality ActDischarge trading controversies

اسلاید 66: Sewage Treatment SystemsRural and suburban areas – septic tankUrban areas – wastewater treatment plantsPrimary treatment – physical processSecondary treatment – biological processChlorination – bleaching and disinfection

اسلاید 67: Primary and Secondary Sewage Treatment

اسلاید 68: Improving Sewage TreatmentSystems that exclude hazardous wasteNonhazardous waste substitutesComposting toilet systems

اسلاید 69: Reducing Water Pollution from Point Sources in the U.S.Impressive achievementsBad news – 2006 survey45% of lakes and 40% of streams too polluted for fishing and swimmingRunoff polluting 7 of 10 riversFish caught in 1/4 of waterways unsafe to eat

اسلاید 70: Should the Clean Water Act be Strengthened?Yes – environmentalistsNo – farmers and developersState and local officials want more discretion

اسلاید 71: Drinking Water QualityPurification of urban drinking waterDeveloped versus developing countries

اسلاید 72: Is Bottled Water the Answer?120 to 7,500 times the cost of tap waterAbout 1/4 is ordinary tap waterAbout 40% of bottled water contaminatedWater testingWater purifiers

اسلاید 73: Methods for Preventing and Reducing Water Pollution

اسلاید 74: What Can We Do?