Desertification

A ship left behind because of the retreat of the Aral Sea

Desertification is the expansion of desert into the surrounding areas. The desert area in the world is getting bigger. Desertification usually happens on the edge of deserts. It is caused by a variety of factors.

Causes

There are many causes of desert spreading:

• Climatic change, including global warming (natural factor). The distribution of rainfall in the surrounding area of desert is uneven. From 1970 onwards, the world's weather has been changing. There has been less rain, and certain areas of the world are becoming drier. Drought affects the area surrounding a desert. As a result, many crops and animals have died. There is no vegetation to protect the soil. The topsoil is removed by sudden flash floods or strong wind. This makes the soil erode and the desert spread towards the surrounding area. Here are a few more ways of desertification:

• Rapid population growth (human factor).
• Overgrazing.
• Deforestation.
• Drought
• Irrigation (if done wrongly, or it needs more water than the environment can provide).

Desertification Media

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  U.S. Department of Agriculture map from 1998 showing global desertification vulnerability

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  Lake Chad in a 2001 satellite image, with the actual lake in blue. The lake lost more than 90% of its surface area between 1987 and 2005.

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  Sun, moon, and large telescopes above Chile's Atacama Desert

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  Telly, one of the first villages in the Bandiagara escarpment in Mali.

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  View of Sydney Harbour Bridge covered in dust

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  A shepherd guiding his sheep through the high desert outside Marrakech, Morocco

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  Anti-sand shields in north Sahara, Tunisia

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  Jojoba plantations, such as those shown, have played a role in combating edge effects of desertification in the Thar Desert, India.

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  Saxaul planted along roads in Xinjiang near Cherchen to slow desertification

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  The Great Green Wall, participating countries and Sahel. In September 2020, it was reported that the GGW had covered only 4% of the planned area.

Other websites

• "Desertification". USGS. Retrieved 2011-11-13.