Tswana “great thirst” still greens after rare good rains
The Kalahari Desert is a 900,000-square-kilometre semiarid sandy savanna across much of Botswana and parts of Namibia and South Africa. From Tswana Kgala (“great thirst”) or Kgalagadi (“waterless place”), it spreads red sand without permanent surface water—yet supports more life than the true Namib to the west.
Strictly speaking, most of it is too thickly vegetated to count as a desert. Only the far southwest, around the Kgalagadi Transfrontier Park, is truly open ground, where plant cover can fall to about 31 percent; elsewhere grasses and camelthorn trees can cover almost everything. The wider Kalahari Basin sprawls over more than 2,500,000 square kilometres into Angola, Zambia and Zimbabwe, and Windhoek sits inside it.
Rain ranges from about 110 millimetres a year in the driest southwest to just over 500 in the north and east, and the sunniest parts log over 4,000 hours of sunshine annually. Because the land lies mostly 800 to 1,200 metres high, winter frosts are common from June to August even though summer peaks pass 40 °C. In summer a heat low builds overhead and helps steer moist Indian Ocean winds across southern Africa.
The region used to be wetter. Fossils from Gcwihaba Cave show abundant plants and permanent water between about 30,000 and 11,000 years ago, and ancient Lake Makgadikgadi may have spread over 120,000 square kilometres before drying roughly 10,000 years ago. Groundwater lingers: Dragon’s Breath Cave holds the largest known underground lake outside glacial ice. Today the Okavango is the only permanent river, fanning into a wildlife-rich delta, while the Makgadikgadi and Etosha salt pans attract tens of thousands of flamingos in the rains.
Lions, cheetahs, brown hyenas, wild dogs, gemsbok and springbok live here, and the kiwano, or horned melon, is native. San hunter-gatherers have lived in the Kalahari for about 20,000 years, drawing water from roots and melons and storing it in ostrich eggshells. After De Beers assessed diamonds at Gope in 1996, San and Bakgalagadi families were evicted from the Central Kalahari Game Reserve from 1997; Botswana’s High Court ruled the eviction unlawful in 2006.
Source: Kalahari Desert
