African Water Development Report 2006 - United Nations Economic ...

African Water Development Report 2006of the main causes of desertification is deforestationwhich lays bare top soils for erosion andearth crusting. Deforestation is a major concern,both for commercial timber and for agriculture.In Africa, forests are lost at an estimated rate ofmore than 5 million ha annually, higher than inany other region. From 1990 to 2000 alone, 60per cent of the tropical forest areas cleared alloverAfrica were converted into permanent agriculturalsmallholdings (UNEP GEO-3, 2002).Inappropriate economic development strategiesand lax implementation of forest protectionregulations are the main causes of the pressureon forest resources. Almost three quarters ofAfrica’s agricultural drylands are already degradedand 73 per cent of these drylands severely ormoderately desertified. Grazing, particularly bycattle, has a serious impact on fragile lands incountries with a large livestock population (fig.6.16). In the Sahel areas, for example, the desertextended 100 km southwards from 1950 to 1975and is said to be extending at an annual rate of 5km in the semi-arid areas of West Africa.About half of Southern Africa is semi-arid andthus at risk of desertification. There, the areasknown to have deteriorated this century aremainly on the edges of the southern Kalahari. Thedeterioration of the Karoo is less well established.It is possible that desertification of the Karoo beganin the last century when sheep were first introduced,and before good records were availablefor the area. In recent years, the introduction ofartificial water points into the Kalahari withinBotswana, together with the widespread erectionof veterinary fences, have led to the rapid desertificationof huge areas. Similar schemes have hadthe same effect in the southern Kalahari withinAngolaBurkina FasoCameroonChadEthiopiaKenyaMadagascarMaliNigeriaSomaliaSudanTanzania.UgandaZimbabweFig. 6.16: Sub Saharan African Countries with High LivestockPopulation0 5000 10000 15000 20000 25000 30000Cattle Sheep GoatsPop. in thousandsExtracted from FAO, 1997156