Kalahari Desert, large basinlike plain of the interior plateau of Southern Africa. It occupies almost all of Botswana, the eastern third of Namibia, and the northernmost part of Northern Cape province in South Africa. In the southwest it merges with the Namib, the coastal desert of Namibia. The Kalahari’s longest north–south extent is roughly 1,000 miles (1,600 kilometres), and its greatest east–west distance is about 600 miles; its area has been estimated at some 360,000 square miles (930,000 square kilometres).


The Kalahari Desert is a featureless, gently undulating, sand-covered plain, which everywhere is 3,000 feet (900 metres) or more above sea level. Bedrock is exposed only in the low but vertical-walled hills, called kopjes, that rarely but conspicuously rise above the general surface. Aside from the kopjes, three surfaces characterize virtually all of the Kalahari: sand sheets, longitudinal dunes, and vleis (pans).


The sand sheets appear to have been formed during the Pleistocene Epoch (about 2,588,000 to 11,700 years ago), and they have been fixed in place since then. In some areas they appear to have been of fluvial origin, the result of sheet flooding in times of much greater precipitation, but by far the greater part of them were wind-formed. The sheets occupy the eastern part of the Kalahari. Their surface elevation varies only slightly, with relief measured in tens of feet per mile. The depth of the sand there generally exceeds 200 feet. In many areas the sand is red, the result of a thin layer of iron oxide that coats the grains of sand.


The entire western Kalahari Desert is characterized by long chains of dunes, oriented roughly to the north or northwest. The dunes measure at least 1 mile in length, several hundred feet in width, and 20 to 200 feet in height. Each dune is separated from its neighbour by a broad parallel depression locally called a straat (“street,” or “lane”), because each constitutes the easy way to travel.


Vleis, or pans, are the terminal features of desert drainage systems, the “dry lakes” at the end of ephemeral streams. Many are remnant features from an earlier period of greater precipitation. Very little water ever flowed to the sea from the Kalahari. Rather, each stream ended its course in a slightly lower depression from which there was no outlet. There, as the stream dried up, the fine silt particles carried in suspension by the sluggish stream were deposited along with soluble calcium minerals and salts precipitated out of the evaporating water. The results are pans—flat surfaces devoid of vegetation that are gleaming white when dry, hardened by the cementing action of the soluble minerals, and, on occasion, covered by a shallow layer of standing water. Where the salt content is low, pans may become covered with grasses after a rain.

Plant life

The presence of a deep sand cover over most of the area greatly affects the vegetation that grows there. Shallow-rooted plants cannot survive on a perennial basis, although annuals that grow very rapidly after a good rain may be able to sow seeds that will endure until the next good rainy season. Trees with roots deep enough to reach permanently moist sand levels do well.



Kalahari desert

Kalahari desertAloe hereroensis, a member of the lily family. Its succulent (water-storing) leaves are well adapted to the arid environment of the Kalahari in South Africa.

The southwestern Kalahari Desert, with its very low precipitation, has few trees or large bushes—only scattered xerophytic (drought-tolerant) shrubs and short grasses. The central Kalahari, with more rain, has scattered trees (several species of Acacia) and some shrubs and grasses. The northern Kalahari does not have the appearance of a desert at all. It has open woodlands, palm trees growing among thorn brush, and forests of both evergreen and deciduous trees that grow to heights of 50 feet and yield some species suitable for timber; one of the largest and most unusual of these trees is the baobab. The Okavango Swamp supports a dense growth of reeds, papyrus, pond lilies, and other water-loving plants.

Animal life



springbok

springbokSpringbok in the Kgalagadi Transfrontier Park, Southern Africa.

The animal life of the Kalahari Desert is also richer and more varied in the north than in the south. Yet even in the arid south, many individuals of several species stay for long periods of the year despite the absence of surface water. The principal species found in the south are springbok, gnu (wildebeest), and hartebeest—all of which occasionally are present in great herds—gemsbok (oryx), eland, and many smaller nongregarious species, such as kudu (in areas of denser brush), steenbok, and duiker.


lion



lionA lioness washing one of her cubs, Kalahari Desert, South Africa.

The northern Kalahari supports a considerable population of giraffes, zebras, elephants, buffalo, and antelopes (roan, sable, tsessebe, and impala); predators such as lions, cheetahs, leopards, wild hunting dogs, and foxes; other large and medium-sized mammals, such as jackals, hyenas, warthogs, baboons, badgers, anteaters, ant bears, hare, and porcupines; and numerous small rodents, several types of snakes and lizards, and a wealth of birdlife.

People and economy

The Kalahari Desert is inhabited primarily by Bantu speakers and Khoisan-speaking San, with a small number of Europeans.


Bantu-speaking peoples

The Bantu-speaking peoples—the Tswana, the Kgalagadi, and the Herero—are relative newcomers to the Kalahari. In the late 18th century the Tswana spread west from the Limpopo basin into the northern and eastern Kalahari; the Kgalagadi moved north and west into the southern and western Kalahari; and the Herero refugees from the German-Herero conflict of 1904–07 in German South West Africa (now Namibia) fled east into the western and northern Kalahari at the beginning of the 20th century.


Those in the remoter parts of the Kalahari who are unaffected by mining or other industry live in villages of between 200 and 5,000 people. Housing is mostly of the traditional type: single-roomed huts with mud walls and thatched roofs. Water is the limiting factor, confining settlement to places situated near wells or boreholes with potable water.


Cattle, the basis of the economy, are kept on the outskirts of villages, or at distances of up to 50 miles away. Wells and boreholes are owned by local government councils, syndicates of cattle owners, or private individuals; year-round cattle grazing is limited to their vicinity. In summers of above-average rains, however, pastoralists may trek with their stock to remote pastures, where for a short time water may occur in pools. Cattle and goats feed upon a small range of the available vegetation. Since effective pasture management is little practiced, the grazing of these animals is highly destructive. Pasture loss and subsequent desertification are serious threats to the ecology of the Kalahari Desert. Cattle are prized beyond their economic value, as their ownership is a measure of social status and personal worth. Thus, the desire to possess more cattle puts an increasing load on diminishing pasture, leaving it no chance for recovery. The traditional dangers to livestock—drought, disease, internal parasites, and wild predators—have diminished markedly as more boreholes have been sunk, veterinary care improved, and indigenous fauna have grown scarcer. In addition, wealthier cattle owners have improved their herds by introducing better stock and practicing scientific breeding.


Goats furnish most of the meat and milk for home consumption, and nearly all households cultivate crops of corn (maize), sorghum, and pumpkins. Because of the threat of drought, more crops fail than are successful. Wild food plants and the meat of game animals are important components of diet in the smaller and more remote villages. All villages have trading stores or are visited by hawkers who sell foodstuffs and other commodities.