The Kalahari Desert is in Southern Africa. 900,000 km from the Kalahari Desert is covering much of Botswana , and parts of Namibia and South Africa. The only permanent river, the Okavango, flows into a delta in the Northwest. The surface is mostly covered with red soil, except in the East where large patches of sand are found. When a heavy rain occures, pans of water form in the extensive mud flats. But the Kalahari is not a true Desert.