GEO DICTIONARY
Sedentary farming: the fencing or enclosure of animals
Sahel, the number of cattle a person owns is a measure of their wealth. With increased cattle herds, the land becomes overgrazed, meaning the soil is being used beyond its carrying capacity. Added to this, farming practices have changed, with sedentary farming now being carried out by many. As the animals are fenced in, the soil is not given a chance to recover its nutrients, and this damages the structure. Animal hooves compact the soil, making it difficult for water to penetrate the surface, increasing the risk of drought and reducing the soil’s fertility. As there is less fertile soil, there is also less vegetation, which makes the soil more susceptible to wind erosion.
In order to provide water for their animals, farmers dig wells and boreholes. This greatly lowers the water table, which is not replenished each year.
Overcropping
With a rapidly growing population, the biggest struggle for the people of the Sahel is food security. This, combined with the growing of cash crops to pay off international debt, has led to the over-cultivation of land. In many cases this has led to monoculture, where one crop is continually grown by farmers. This causes soil minerals to become depleted. Farmers are unable to pay for artificial fertilisers and cattle dung is used as a fuel for cooking. With each passing growing season, the soil becomes less and less fertile until eventually it becomes barren.
Deforestation
Much of the Sahel region was once covered in trees and bushes. Many of these trees have been removed in order to make way for agricultural land or to create firewood.
Firewood is an important resource in the Sahel, as it is used for cooking and heat. It is the only fuel resource in the Sahel, as the region lacks deposits of fossil fuels. Population growth of over 3 per cent per annum has led to an increased demand for fuel and has accelerated the rate of
: Fig. 2.13 Deforestation in the Sahel
deforestation. The removal of this forest cover exposes the soil to intense heat, flash floods and strong winds.
Effects of Overpopulation
Environmental Degradation Due to climate change and the overuse of natural resources in the Sahel, the region’s environment is being severely damaged. Desertification (the spread of deserts) is increasing as the Sahara Desert advances 5–10 km per year. The exposed dry soil is eroded away by winds and flash floods. As the winds carry away the topsoil, huge dust storms are generated, often measuring several hundred metres in height. Mauritania is an example of a country in which this is occurring, with over 100 million tonnes of topsoil
46 ELECTIVE 5 PATTERNS AND PROCESSES IN THE HUMAN ENVIRONMENT
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