Desertification

What Is desertification
Desertification is the degradation of land, resulting primarily from man-made activities. It is principally caused by overgrazing, overdrafting of groundwater and diversion of water from rivers for human consumption and industrial use, all of these processes fundamentally driven by overpopulation.

Major impacts of desertification is biodiversity loss, which is basically the health of the biodome and biosystem in the area.

The primary reasons for desertification are overgrazing, over-cultivation, increased fire frequency, water impoundment, deforestation, overdrafting of groundwater, increased soil salinity, and global climate change. Seventy percent of the world's drylands (excluding hyper-arid deserts), or some 3,600 million hectares, are degraded.

While drought is often associated with land degradation, it is a natural phenomenon that occurs when rainfall is significantly below normal recorded levels for a long time. It is also the leading cause of stream, lake, and river recession. Some key contributors to Desertification are;


 * Destruction of vegetation in arid regions, often for fuelwood.


 * Poor grazing management after accidental burning of semi-arid vegetation.


 * Incorrect irrigation practices in arid areas can cause salinization, (the build up of salts in the soil) which can prevent plant growth.

When the practices described above coincide with drought, the rate of desertification increases dramatically.

Increasing human population and poverty contribute to desertification as poor people may be forced to overuse their environment in the short term, without the ability to plan for the long term effects of their actions. Where livestock has a social importance beyond food, people might be reluctant to reduce their stock numbers.

Desertification reduces the ability of land to support life, affecting wild species, domestic animals, agricultural crops and people. The reduction in plant cover that accompanies desertification leads to accelerated soil erosion by wind and water. For instance, South Africa is losing approximately 300-400 million tonnes of topsoil every year. As vegetation cover and soil layer are reduced, rain drop impact and run-off increases.


 * __//Useful links//__**

Fact Sheets of the UNCCD, U.N.C.C.D. (2007). What is desertification. 1, Retrieved from http://www.gdrc.org/uem/Trialogue/whatis-desert.html

Wikipedia W. (2004). Desertification. Wikipedia. Retrieved (2009, september 04) from http://en.wikipedia.org/wiki/Desertification