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Stimulus material: What comments can you make about this photo ?. Desertification. http://www.youtube.com/watch?v=DOUu-vHal7E http://www.youtube.com/watch?v=WEX-kqK8c4k&feature=related. What is it ?. - PowerPoint PPT Presentation
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Desertificationhttp://www.youtube.com/watch?v=DOUu-vHal7Ehttp://www.youtube.com/watch?v=WEX-kqK8c4k&feature=related
What is it ?
Desertification is the spreading of deserts, or desert soil conditions and vegetation, into areas of semi-desert land that once used for farming or grazing.
Causes:ÒDroughtÒToo much grazingÒPoor irrigation/incorrect irrigation practicesÒHarmful agricultural practicesÒClearing of treesÒIncreasing population size of an areaÒCultivation of marginal landsÒDestruction of vegetation
When droughts occur and there is not enough vegetation to bind the soil, the winds and water can cause large-scale erosion.
Desert conditions then move into areas which were once able to support a large number of communities and grazing practices.
Effects of Desertification
Communities are displaced and have to migrate elsewhere. This can lead to conflict as they move into other areas already occupied.
Declining water tables Salinisation of topsoil and water Less surface water High soil erosion Loss of native vegetation Loss of flora and fauna