Showing posts with label desertification. Show all posts
Showing posts with label desertification. Show all posts

Tuesday, 24 June 2014

Sahel

The Sahel is a region in West Africa. 






It is a strip of dry land about 5500 kilometres long and 450 kilometres wide. The Sahel covers parts of (from west to east) the Gambia, Senegal, southern Mauritania, central Mali, Burkina Faso, southern Algeria and Niger, northern Nigeria and Cameroon, central Chad, southern Sudan, and northern South Sudan. It lies at the southern edge of the Sahara Desert and is located between the dry desert land to the north and the forest areas to the south.




Climate
The Sahel has a semi-arid climate. The temperature is high throughout the year. 
There is little rainfall in the Sahel (between 100-150 mm and 600mm). It is concentrated during summer months and can be unreliable. It may be very dry in some years, especially if a large area of low pressure, which brings rain, is not carried North over the Sahel by strong winds.




Desertification
The Sahel is facing a big problem, Desertification. The distribution of rainfall in the Sahel region is uneven. The rainfall in the region has been below average since 1970. The Sahel is becoming drier on the whole. The problem of drought affects most of the countries. As a result, crops and animals die. 




Soil erosion
There is no vegetation to protect the soil, which is then removed by flash floods and strong wind. This leads to soil erosion. 




Deforestation
The population in the Sahel is growing. To meet the ever-increasing demand for firewood, a lot of trees have been cut down. More land has become barren. This is called deforestation. 




Overcultivation
Because people farm intensively in order to grow more crops, the soil becomes dry and infertile. If this process continues for a long time, no crops can be grown. This is called overcultivation. 



Overgrazing
People keep many animals for food. However, the grass cannot support so many grazing animals. This is called overgrazing. 


Wednesday, 16 November 2011

Deserts of the world





Deserts cover about one-seventh of the earth's land surface. Desert regions cover 35% of the earth's surface.
Deserts are landscape forms or regions that receive little precipitation. They are cold at night and since the desert air is dry it holds little moisture. Desert regions receive an average annual precipitation of less than 250 mm.

Wednesday, 12 October 2011

Desertification

www.youtube.com/watch?v=tDWS6AzEkE0

http://www.youtube.com/watch?v=zlSoQWXJemw&feature=related

Both videos show the process of desertification and what the impacts are on the Sahel region.


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