Desertification is a process of continuous, gradual ecosystem degradation, during which plants and animals, and geological resources such as water and soil, are stressed beyond their ability to adjust to changing conditions.
Overgrazing is the major cause of desertification worldwide. Other factors that cause desertification include urbanisation, climate change, overdrafting of groundwater, deforestation, natural disasters and tillage practices in agriculture that place soils more vulnerable to wind.
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. South Africa 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.