Kalahari Desert

Arid to semi-arid desert area, occupying a plateau and forming most of Botswana and extending into Namibia, Zimbabwe, and South Africa; area about 900,000 sq km/347,400 sq mi. The only permanent river, the Okavango, flows into a delta in the northwest, forming marshes that are rich in wildlife. The British explorer, David Livingstone, crossed the Kalahari in 1849.

Physical features The Kalahari forms an extensive tract of country in southern Africa, including the eastern part of Namibia, part of South Africa north of the Orange River, most of Botswana as far east as the main railway, and a large part of southwest Zimbabwe. While generally regarded as a desert, only the southwest Kalahari is truly arid, although the whole area is covered by fine sandy soil. There is little surface water, although seasonal rains support substantial trees, shrubs, and grass. Drainage features are dominated by dry valleys, seasonally inundated pans (which are flat areas covered during dry periods by salts precipitated from evaporating water), and the large salt pan complexes of the Makgadikgadi Depression in Botswana and Etosha Pan in Namibia.

Water Annual rainfall varies from 175 mm/7 in on the southern fringe to 575 mm/23 in in the extreme north. The sand is so uniform and the land so level that, except for the Cunene, Okavango, and rivers of the Zambezi system, no other river produces an annual flow. The Okavango Delta is the major area of permanent standing water. In many places, after the summer rains have ended, the sole supply of water comes from the pans, with local inhabitants often reliant on boreholes.

Agriculture In the parts with higher rainfall there is good grazing, but it is extremely vulnerable and demands very careful pasture management. Only along the Okavango and Cunene rivers are there any irrigation possibilities. All development is hampered by poor transport facilities, although the infrastructure is rapidly improving with the construction of a major network of roads, including the Trans-Kalahari Highway linking Gaborone to Windhoek.

Wildlife In the more densely inhabited areas much wildlife has disappeared, although large herds still exist in remoter parts, especially where there is protection, as in the Etosha Game Reserve and the Kalahari Gemsbok National Park.

Indigenous population The Kalahari is inhabited by the Khoikhoi, San, and Kung people. (See also Bushmen.)