Desertification

Definition

Ø It turns productive land into unproductive land, primarily as a result of human rather than natural forces.

Ø Desertification affects 25% of the world¡¦s total land resources. Half of the Africans affected by desertification live in the Sahel region.

What Causes Desertification?

1. Overuse of the land

Ø by overgrazing or by overcropping the land

Ø particularly in marginal areas

2. Population growth

Ø As rural populations increase, they need to produce more mad more food from a fixed amount of land,

Ø leading to overuse of the land.

3. Changing economies

Ø People are under pressure to shift from the production of subsistence crops to cash crops

Ø for sale in the cities or on the international market.

4. Droughts and climatic change

Ø They make land more vulnerable to overgrazing and overcropping.

What are the Effects of Desertification?

Ø Declining crop yields, as soils are eroded and nutrients depleted by erosion

Ø Less plant and grass cover, which means that less food is available for livestock

Ø Fewer trees, so that people need to travel further and further to find wood for fires or for building

Ø High rainfall runoff. Without adequate vegetation cover, rainfall runoff is high and water absorption by the soil is low. This results in increased flooding, reduction of available water, and depletion of ground water.

Ø Social disruption. As food resources are depleted, people are forced to leave the land as environmental refugees, and migrate to other rural areas or cities.