The Kalahari Desert is a large, arid to semi-arid sandy area in southern Africa that covers about 500,000 km². It covers 70% of Botswana, and parts of Zimbabwe, Namibia and South Africa. Some sources would extended the area of the Kalahari to over 2.5m km² and include Gabon, Congo, the Democratic Republic of the Congo, Angola, and Zambia.
The Kalahari has vast areas covered by red-brown sands and has no permanent surface water. Drainage is by dry valleys, seasonally inundated pans, and the large salt pans of the Makgadikgadi Depression in Botswana and Etosha Pan in Namibia. However, the Kalahari is not a true desert. Parts of the Kalahari receive over 250 mm of erratic rainfall annually and are quite well vegetated; it is only truly arid in the south-west (under 175mm of rain annually) making the Kalahari a fossil desert. Summer temperatures in the Kalahari range from 20 - 40 °C. In winter, the Kalahari has a dry, cold climate with frosts at night. The average low winter temperature can be below 0 °C.
The Kalahari has a number of game reserves - the Central Kalahari Game Reserve (CKGR, the world's second largest protected area), Khutse Game Reserve and the Kgalagadi Transfrontier Park. Animals that live in the region include brown hyenas, lions, meerkats, several species of antelope (including the oryx or gemsbok and the tsamma), and many species of bird and reptile. Vegetation in the Kalahari consists mainly of grasses and acacias but there are over 400 identified plant species present.
The area is inhabited by the Khoikhoi and San (!Kung or Bushmen) people. The people themselves prefer the name "Bushmen" to "San". They were the first known human inhabitants of the Kalahari, and are believed to have been living there continuously as hunter-gatherers for at least twenty thousand years. Their survival skills and adaptation to the Kalahari are impressive, but only a small number of the Bushmen still follow their traditional way of life in the Kalahari. In 2002 all Bushmen were frocibly expelled from their lands within the borders of Botswana by the Botswanan government. The official line is that this was for nature conservation reasons, but it is widely believed that the real reason was to free up their lands for diamond mining.
There are large coal, copper, and nickel deposits in the region. One of the largest diamond mines in the world is located at Orapa in the Makgadikgadi, northeastern Kalahari.
Kalahari is derived from the Tswana word "Kgalagadi", meaning "the great thirst".