Kalahari Desert - geography.

Kalahari Desert - geography. I INTRODUCTION Kalahari Desert, arid region on the interior plateau of southern Africa, occupying central and southwestern Botswana and parts of west central South Africa and eastern Namibia. The desert covers an area of about 260,000 sq km (100,000 sq mi). The Kalahari is part of a large sand basin stretching into Angola and Zambia in the north, through Botswana into Zimbabwe in the east, south to the Orange River in South Africa, and west to the highlands of Namibia. This basin has a total surface area of about 930,000 sq km (360,000 sq mi). The name Kalahari is derived from the Tswana word Kgalagadi, meaning "the great thirst." II LAND AND RESOURCES The Kalahari is mostly flat, with an average elevation of about 1,000 m (3,000 ft) above sea level. The sands of the Kalahari are red, brown, or white in places. Parallel lines of dunes--typically lying along a north-to-south or northwest-to-southeast orientation, depending on the prevailing winds--cover substantial areas of the Kalahari, and are concentrated in the west. The dunes vary in height from about 6 m (20 ft) to 60 m (200 ft), are separated by channels of varying width, and can be up to 80 km (50 mi) long. The Kalahari has a semiarid climate, and droughts are frequent. The region receives about 200 mm (8 in) of precipitation a year, mainly between the months of October and May. The rainfall pattern is highly variable, however, and precipitation can fluctuate by more than 100 percent between years. Daytime temperatures range between 35° to 45°C (95° to 113°F) from October to March, the hottest months, and can drop below freezing between June and August. The only permanent surface water in or around the Kalahari is the Boteti River. The Boteti flows out of the Okavango Delta, an extensive swampy region at the northern edge of the Kalahari Desert in northern Botswana. Heavy rains in central Angola cause periodic flooding of the delta, and the Boteti carries the overflow east into Lake Xau and the Makgadikgadi Pan on the northeastern fringe of the desert. Other channels carry water south into Lake Ngami. Elsewhere in the desert, short-lived networks of streams and rivers flow after rains. Subterranean water can be found below the temporary watercourses. These streams flow into depressions in the desert, known as pans. Pans vary in size from a few meters to tens of kilometers in diameter, and provide temporary or semipermanent sources of surface water. The Kalahari contains a mix of acacia woodland, acacia scrub, savanna grasslands, and palm trees. Wildlife in the Kalahari has adapted to survival without a permanent water supply. Antelope such as eland, gemsbok, springbok, hartebeest, steenbok, kudu, and duiker are common, as are giraffe, warthog, hyena, jackal, the bat-eared fox, the rare wild dog, and a host of smaller animals and many species of birds. Plant species are most diverse around pans and these areas are a rich food resource for animals. The largest protected areas in the Kalahari are the Central Kalahari Game Reserve in Botswana and the Kgalagadi Transfrontier Park, shared by Botswana and South Africa. III PEOPLE AND ECONOMY The sparsely populated Kalahari is inhabited by the Khoisan-speaking San people, the Bantu-speaking Tswana, Kgalagadi, and Herero, and a small number of European settlers. Most San live in reserves and villages in and around the Central Kalahari Game Reserve, in northeastern Namibia, or in northern South Africa. Traditionally hunter-gatherers, the San are increasingly involved in cattle farming, often as laborers. Today, less than 5 percent of the San people still practice their traditional hunter-gatherer economy and lifestyle. The Bantu-speaking people of the Kalahari generally raise livestock for a living. This activity is concentrated in the eastern Namibian and Botswana portions of the desert. In Botswana, major towns in the Kalahari include Ghanzi, Tshane, Tshabong, and Orapa. In the Namibian portion of the Kalahari, the villages of Gobabis and Mariental are important regional centers. Rietfontein, Noenieput, and Severn are important South African towns in the desert. Tourism is an important and growing industry in the Kalahari, although the remote location of many game reserves and the generally poor transport and hospitality infrastructure are limiting factors. The Kalahari is rich in minerals, particularly in Botswana. The Orapa diamond mine opened there in 1971 and diamond mining soon became a key part of the Botswana economy. A sparse network of roads and tracks serves the Kalahari. In Botswana, the paved Trans-Kalahari Highway connects all major mining, commercial, and farming areas. Other roads are gravel or sand. In Namibia, the urban areas are served by paved roads, and the smaller settlements by gravel and sand roads. IV HISTORY OF THE KALAHARI The San have lived in the Kalahari Desert for more than 30,000 years. Bantu-speaking Tswana and Kgalagadi arrived by 1800, the Tswana migrating north from what is now South Africa and the Kgalagadi from the east. Europeans entered the region in the early 19th century, primarily as missionaries, hunters, and traders, but few settled in the Kalahari. In 1849 Scottish explorer and missionary David Livingstone crossed the desert, finding Lake Ngami. In the late 19th and early 20th centuries, Herero peoples migrated into the Kalahari from the west. In the second half of the 20th century settlement in the Kalahari increased as mining and tourist operations grew. Today, perhaps the largest threat to the Kalahari is rising livestock populations and the associated destruction of the desert's scant plant life. Contributed By: David McDonald Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.