Presented By : Talha ArfiRegistration # 20090498
PRESENTATION SCHEMEWhy Dams?What is Dam?Types of DamsUses Of DamsDams-StatisticsImpacts of DamsConclusion
WHY DAMS?Water is essential for sustaining all life.Population movement and increase require water year round in remote areas.Water collection and utilization is important.Ability to sustain dough and dry situations.
WHAT IS DAM?A structure to contain water.A solid barrier constructed at a suitable location across a river valley.Has mechanically engineered structure to direct and control flow of water and storage.
TYPES OF DAMS Gravity Dam Arch DamButtress Dam Embankment Dam
DAMS STATISTICSBy the end of the 20th century , there were 45,000 large dams built in 150 countries . International Commission on Large Dams (ICOLD)Displacement of 4 million people annually due to dams.Approximately 1,700 dams are being built , at the cost of about 50 million dollars per year.19% of electricity from hydro power-more than 50% in 63 countries.12% of all dams have a water supply function.75 countries have dams for flood control.Dam supports 30-40% of irrigated area and 12-16% of global food production. World Commission on Dams (WCD)
IMPACTS OF DAMSEnvironmental ImpactsSociological ImpactsEconomical ImpactsEffects of Dams on Water Quality
Environmental ImpactsRiver PollutionErosionLoss of Aesthetic ViewAir PollutionNoise PollutionDust
SOCIOLOGICAL IMPACTSIndigenous People AffectedLoss of EcosystemsLoss of SpeciesDisplacement Of People
EFFECTSON WATER QUALITYChange in TemperatureTurbidityDissolved Gas in the WaterEutrophication
CONCLUSIONSmall dams should be built instead of large damsCareful planning throughout the site selection , design and construction of dam is criticalSociological impacts should be considered along with the main objectives of water supply , power generation and flood controlEconomic incentives should be weighed against sociological impacts