The Kalahari Desert a large semi-arid sandy savannah in Southern Africa extending 900,000 square kilometres, covering much of Botswana and parts of Namibia and South Africa.
The Kalahari is formed in a region of subsidence in the Hadley cell known as the “horse latitudes” and also its continentality.
The surrounding Kalahari Basin covers over 2,500,000 square kilometres extending further into Botswana, Namibia and South Africa, and encroaching into parts of Angola, Zambia and Zimbabwe.
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.
Among deserts of the southern hemisphere the Kalahari most closely resembles some Australian deserts in its latitude and its mode of formation.
Vegetation in the Kalahari consists mainly of grasses and acacias, but there are over 400 identified plant species present (including the wild watermelon, or Tsamma melon). Camel rides flourish when it rains.
The Kalahari has vast areas covered by red sand without any permanent surface water. Drainage is by dry valleys, seasonally inundated pans, and the large salt pans of the Makgadikgadi Pan in Botswana and Etosha Pan in Namibia. However, the Kalahari is not a true desert. Parts of the Kalahari receive over 250 millimetres of erratic rainfall annually and are quite well vegetated; it is only truly arid in the southwest with less than 175 millimetres of rain annually, making the Kalahari a fossil desert.
Summer temperatures in the Kalahari range from 20 to 45°C (68 to 113°F). Temperatures occasionally reach up to 50 °C (122 °F). In the driest and sunniest parts of the Kalahari, over 4,000 hours of sunshine are recorded annually on average.
Despite its aridity, the Kalahari supports a variety of fauna and flora. The native flora includes acacia trees and many other herbs and grasses. The Kiwano fruit, also known as the Horned melon, melano, African horned cucumber, jelly melon, hedged gourd, and/or English tomato, is endemic to a region in the Kalahari Desert.
Some of the areas within the Kalahari are seasonal wetlands, such as the Makgadikgadi Pans of Botswana, supports numerous halophilic species, and in the rainy season, tens of thousands of flamingos visit these pans.
The Kalahari has a number of game reserves—Tswalu Kalahari, South Africa’s largest private game reserve, the Central Kalahari Game Reserve (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, giraffes, warthogs, jackals, several species of antelope (including the eland, gemsbok, springbok, hartebeest, steenbok, kudu, and duiker), and many species of birds and reptiles.