2Water“Water Planet”- Earth has an abundance of water in all forms: solid, liquid, and gas.Renewable resource because it is circulated in the water cycle.Humans can only survive a few days without water.Two kinds of water on Earth:Fresh water- Can drink because it contains little salt.Salt water- Ocean water with a high concentration of salt.
4Global Water Distribution 97% salt water3% fresh water77% of fresh water frozen in icecaps and glaciers22% ground water1 % other
5Global Water Distribution Surface water- Fresh water on Earth’s land surface.Lakes, rivers, streams, and wetlandsRiver systems- Flowing network of water comprised of streams and rivers.Amazon river system- largest in the worldWatershed- Area of land that is drained by a river.
7Global water Distribution Ground Water- Water stored beneath the Earth’s surface in sediment and rock formations.Water table- Level where the rocks and soil are saturated with waterAquifer- Underground formation that contains waterPorosity- Amount of space between the particles that make up a rock.Permeability- The ability of rock or soil to allow water to flow through it.Permeable- Allows the flow of water.Impermeable- Does not allow the flow of water.
8Ground Water- Cont’d.The Recharge Zone- The area of the Earth’s surface where water percolates down into an aquifer.Wells- A hole that is dug or drilled to reach groundwater
9Water Use and Management Chapter 11-WaterWater Use and Management
10Global Water Use Most freshwater used globally to water crops. 19% of global water use for industryOnly 8% of global water used for washing and drinking.
11Residential Water UseStriking differences among countries around the worldU.S. residents use on average 300 L of water per dayIndian residents use on average 41 L of water per day
12Water Treatment Potable- Safe to drink. Treatment must remove elements: mercury, arsenic, and leadFound in polluted and ground waterPathogens- Organisms that cause illness or diseaseSee Figure 6, Pages
14Water Use Industrial- 19% of water use in world Manufacture goodsDispose of wasteGenerate powerMost used to cool power plantsAgricultural- 67% of water use in world80% of water used in agriculture evaporatesIrrigation- Method of providing plants with water from sources other than direct precipitation.
16Water Management Projects Aqueducts- Huge canals that brought water from the mountains to dry areas.Dams and water diversion canals used today.Water management projects today:Bring in water to make a dry area habitableCreate a reservoir for recreation or drinking waterGenerate electric power
17Water Management Projects Water Diversion Projects- To supply dry regions with water, all or part of a river can be diverted into canals that carry water across great distances.
18Water Management Projects Dam- Structure built across a river to control the river’s flow.Can be used to generate electricity.Problems: flooding, ecosystem destruction, and dam failureFertile sediment builds up behind damsReservoir- Artificial lake formed behind a dam.
19Water Conservation Water becomes more expensive as it depletes. Agriculture: Most water loss from evaporation, seepage, and runoffDrip Irrigation System- Small amounts of water delivered directly to roots using perforated tubing.
20Water Conservation Home: Industry: Water-saving technology such as low-flow toilets and shower headsWater lawns at nightXeriscaping- Designing landscapes that require minimal water use.Industry:Recycling of cooling water and wastewaterCity wide/company wide water saving plans
21Solutions for the Future Desalination- Process of removing salt from salt waterHeats water and collects evaporationMiddle East/Kuwait has desalination plantsTransporting WaterTransporting in bags and/or large plastic containers from abundant supplies to low supplied regionsTowing icebergs??
23Water PollutionThe introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water.
24Types of Water Pollution Nonpoint-source PollutionPollution that comes from many different sourecsDifficult to identify and trace/regulate and control96% of polluted water in U.SPoint-source PollutionPollution discharged from a single sourceCan be identified and traced.
26Wastewater Water that contains waste from homes or industry. Treating Most contaminates are biodegradableSome toxic substances cannot be removed by standard treatment
27Wastewater Sewage sludge Solid material that remains after treatment Sometimes hazardous wasteOften incinerated and ash buriedCan be used as fertilizer or bricks
28Water Pollution Eutrophication Containing an abundance of nutrientsLeads to swamp or marshArtificial Eutrophication- Sewage and fertilizer runoff enhancesEx: Algal bloomsThermal Pollution- Increased temperature of water sources caused by factories and industries cooling systemsDecreases oxygen levelsKills organisms
29Water PollutionGroundwater pollution- Polluted surface water percolates down to groundwaterLeaking underground storage tanks are large problemRemains for 100s to 1000s of yearsOcean pollutionCoastal ecosystems most affectedLegal to dump in some parts of oceanOil spills5% of ocean pollutionNonpoint-source pollution from land 10 times more than tanker spills
31Water PollutionBiomagnification- Accumulation of pollutants at successive levels of the food chain.Many pesticidesExample: DDT and the Bald EagleClean Water Act of To restore and maintain the chemical, physical, and biological integrity of the nation’s waters.Goal to make fishing and swimming safe by 1983.Not achieved30% increaseOpened door for more legislation