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1999-10 : Wushengy (Gansu Province China) - Authorities on an evaluation mission of the Belgian TC-Dialogue's anti-desertification project : construction of 15 family greenhouses on the Gobi-plateau (Photo WVC)
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DESERTIFICATION: The Sands of Change, United Nations Environment Programme
The United Nations Environment Programme (UNEP) estimates that about 3500 million hectares of land… an area the size of North and South America combined are affected by desertification. Every year about 6 million hectares of land are irretrievably lost to desertification, and a further 21 million hectares are so degraded that crop production becomes uneconomic.
While the terms “desertification” and “land degradation” are only now coming into popular usage, the problem has afflicted mankind for centuries. Historians believe, for example, that desertification played a role in the downfall of the Sumerian, Babylonian, Harappan and Roman civilizations.
Today many parts of the world’s arable land is in jeopardy as is shown in the map above identifying existing deserts and those areas at high and moderate risk of becoming degraded.
Many believe that drought brings on encroachment of deserts and while drought can accelerate desertification, it is rarely caused by it.
The causes of desertification are varied and complex but it’s important to emphasize that desertification is caused largely by human action… or the lack of it. Overgrazing, deforestation, intensive cash cropping on marginal land, poor management of wells and drilling and the settling of previously nomadic peoples all play a role.
One of the commonest causes of desertification is the salinization of irrigated land. Today nearly as much land is currently being lost to water logging and salinization as is being newly irrigated. Unless new irrigation methods pay careful attention to drainage, many areas will ultimately suffer from salinity, just as was the case with many of the great civilizations of the past.
Since desertification is caused by human action it can be cured and controlled by human action. The solutions are not technically difficult.
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