Only about 7% of South Africa has a mean annual precipitation or MAP exceeding 800 mm. When the statistics are reviewed they indicate that KwaZulu-Natal is the wettest province, while the Western Cape has the highest variability of MAP within any of the provinces, and the highest individual point rainfall at an estimate of 3345 mm per annum is located along the southern mountain ranges of the province.
The eastern provinces, KwaZulu-Natal, Eastern Cape to a lesser degree, Mpumalanga, Gauteng and to an extent, Northern Province, receive more rain than the provinces in the west (such as the North West Province, Northern Cape, or the Free State). The Northern Cape receives the lowest mean annual precipitation with Western Cape the second lowest.
Northern Cape 202
Western Cape 348
North West 481
Northern Province 527
Free State 532
Eastern Cape 552
Drylands and desertification
Nearly 91% of South Africa falls within the United Nations’ definition of affected drylands. These are extraordinarily dry areas where the rainfall is low, and the potential evaporation is high. Dryland systems are often very sensitive to change and therefore need to be managed carefully. For example, crops grown in these areas are usually not irrigated, and therefore depend on rainfall. Drought-induced crop failure can result in direct food shortages at a local level, usually affecting subsistence agriculturists the hardest. Removal of vegetation (ground cover) from dryland areas can increase the risk of soil erosion, making the soil less fertile, and less able to support (natural and cultivated) crops in future.
Desertification refers to the degradation of land in the dry areas of the world, primarily caused by human activities. Desertification is not the spread of existing deserts. It is the destruction of productive land in dry areas mainly as a result of misuse or overuse. Desertification affects 900 million people in 99 countries, by destroying the capacity of the soil to support livestock or crops. According to a recent national survey, land in nearly 25% of the magisterial districts of South Africa has already been badly degraded.