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Environmental concernscase study on the Aral Sea: Objectives: Understand the environmental concerns surrounding the Aral sea:1.Locate and describe the environmentsurrounding the Aral sea.2.Explain the environmental problemsassociated with the loss of area of the Aralsea.3.Explain the causes of the problem.4.Explain and evaluate the methods possibleto restore the Aral sea.
The Aral sea is located between Kazakhstan and Uzbekistan in what was once the old soviet union.It is fed by 2 rivers: the Syr Darya and the Amu Darya.
Climate of the Aral sea region (temperature)Temperature ranges from -13 to 28 °C. from March toNovember evaporation will take place reducing the waterlevel in the lake unless recharged by rain or river flow.
Climate of the Aral sea region (rainfall).The animation shows that for most of the year there is little or no rainfall. Thisco-insides with the period of prolonged high temperatures seen in theprevious slide. The result is that the climate of the area does not help theAral sea recharge. Instead it has to rely on its two rivers to re-supply water tokeep the lake from drying up.
This satellite image has been annotated to show whathas happened to the lake! Describe what has occurred.
Using the climate data seen before suggest what reasons therecould be for the sequence of events below.
The consequences of the lake reducing in size:Environmental problem: Knock on effect:
Causes of the Aral sea disaster:The diagram on the rightshows the availability ofwater supplies to themain rivers as the bluebar.The level of waterextraction is shown inred.Describe the availabilityof water vs the extractionand suggest what theeffects will be. Combinethe climatic data in youranswer for higher marks.
Analysis of the solution impact pros Cons.solutions to restore the Aral sea. Pump in sea water.Because the Aral sea was Re-routeable to survive despitethe climatic conditions water.before humans Build dams.intervened there is noreason why it cannot be Plantre-filled. However, even if differentthe water is returned crops.there are no guaranteesthat the ecology will Use fewerrecover. Even if it does it chemicals.will take a large numberof years. A set of Droughtproposals has been resistantidentified that could be cotton.used to restore the waterlevels in the Aral sea. For Charging foreach assess its impact water use.and the pros and consfor its implementation. Desalination. Irrigation channels
Answers:Pump in sea water: would slowly re-fill the sea. Easy toachieve and plentiful supply of water. Would allow cottonfarming to continue. No loss of water in transit as piped.However, infrastructure required and would cost a lot. Alsoproblem with environmental cost of powering the pumps.Re-route water: would allow sea to reform. Easy to achieveand permanent move. Not very environmentally damaging.Problems includes loss of farming and visual impact. Waterstill lost through evaporation.Build dams: stops the flow of water from leaving the seaallowing it to rebuild. The most effective solution butcompletely damages the environment and water ecosystemsbelow the dam. Huge cost and visual impact.Plant different crops: will allow less water needed forirrigation so rivers are higher. Problems of having to re-trainfarmers and reduced income.
Use fewer chemicals: area becomes organic in 10 years timefrom start. Reduces the cost. Allows more natural species toreturn. Problems with insect pests and disease. Possiblereduced growth of plants and therefore income that can begenerated.Drought resistant cotton plants: less water needed forirrigation. Will protect from effects of global warming. Plantsare more expensive and generate less cotton per plant somore land required to grow the same yield.Charging for water use: designed to force people to use lesswater. Generates problems between rich and poor. Not veryeffective. Rich will still not reduce their consumption.Desalination: the removal of salt from sea water allows forthis to be used for humans. Infinite supply. Very expensiveand water has to be pumped from sea to land when existingwater supplies go in the other direction.Irrigation channels: same as for re-routing water.
Possible exam questions:There has been no exam yet but expect the following types of questionsin the exam.1.Describing the environment of the area.2.Describing the rate of shrinkage (source E page 5).3.Describing the rate of shrinkage or the area lost (projections on page5).4.Explaining the climate of the area.5.Explaining the causes of the loss of water level (source F page 6).6.Explaining the ecological problems created as a consequence of thewater level dropping (source F).7.Explaining the economical problems created as a result of the waterlevels dropping (source F).8.Assessing the solutions to restore the area back to its original state(source G page 7).9.Decision making to pick some of the options to implement andjustifying your decision.10.Assessing the effectiveness and costs of implementing the solutionsand their chance of success.