Kalahari Desert has too dense a ground cover. The main region that lacks ground cover is in the southwest Kalahari (southeast of Namibia, northwest of South Africa and southwest of Botswana) in the south of the Kgalagadi Transfrontier Park. For instance in the ZF Mgcawu District Municipality of South Africa, total vegetation cover may be as low as 30.72% on non-protected (from cattle grazing) farmlands south of Twee Rivieren Rest Camp and 37.74% in the protected (from cattle grazing) South African side of the Kgalagadi Transfrontier Park : these southernmost Kalahari xeric savanna areas are truly semi-deserts. However, in all the remaining
Kalahari Desert annual rainfall ranging from around 110 mm (close to aridity) to more than 500 mm in some areas of the north and east. During summer time in all regions rainfall may go with heavy thunderstorms. In the driest and sunniest parts of the Kalahari, over 4,000 hours of sunshine are recorded annually on average. In the Kalahari, there are two main mechanisms of atmospheric circulation, dominated by the Kalahari High anticyclone: There are huge subterranean water reserves beneath parts of the Kalahari; the Dragon's Breath Cave, for example, is the largest documented non-subglacial underground lake on the planet. Such reserves