Kalahari Desert

The Kalahari Desert is a large semi-arid sandy savanna in Southern Africa extending for , covering much of Botswana, as well as parts of Namibia and South Africa. It is not to be confused with the Angolan, Namibian, and South African Namib coastal desert, whose name is of Khoekhoegowab origin and means "vast place". Kalahari is derived from the Tswana word Kgala, meaning "the great thirst", or Kgalagadi, meaning "a waterless place"; the Kalahari has vast areas covered by red sand without any permanent surface water. The Kalahari Desert was not always a dry desert. The fossil flora and fauna from Gcwihaba Cave in Botswana indicates that the region was much wetter and cooler at least from 30 to 11 thousand BP (before present), especially after 17,500 BP. Drainage of the desert is by dry black valleys, seasonally inundated pans, and the large salt pans of the Makgadikgadi Pan in Botswana and Etosha Pan in Namibia. The only permanent river, the Okavango, flows into a delta in the northwest, forming marshes that are rich in wildlife. Ancient dry riverbeds—called omuramba—traverse the central northern reaches of the Kalahari and provide standing pools of water during the rainy season. A semi-desert, with huge tracts of excellent grazing after good rains, the Kalahari supports more animals and plants than a true desert, such as the Namib Desert to the west. There is little rainfall, and the summer temperature is very high. The driest areas usually receive of rain per year, and the wettest just a little over . The surrounding Kalahari Basin covers over extending farther into Botswana, Namibia, and South Africa, encroaching into parts of Angola, Zambia and Zimbabwe. Numerous pans exist within the Kalahari, including the Groot-vloer Pan and Verneukpan, where evidence of a wetter climate exists in the form of former contouring for capturing water. This and other pans, as well as river bottoms, were written about extensively at Sciforums by an article by Walter Wagner regarding the extensive formerly wet areas of the Kalahari.