Friday, December 4, 2009
The Great Kalahari Desert
The Kalahari is one of Africa's last wildlife paradises. Animals that live in the region include brown hyenas, lions, meerkats, several species of antelope, and many types of birds and reptiles. Vegetation in the Kalahari consists of dry grassland and scrubby acacias. Grasses thrive in the Kalahari during the summer rainy season. African people known as the San (or Bushmen) were the first known human inhabitants of the Kalahari.
Their survival skills and adaptation to the harsh Kalahari wilderness have become legendary. Today, only a small number of the San follow their traditional way of life in the Kalahari. Modern civilization is threatening the natural resources of the Kalahari. Mineral companies have discovered large coal, copper, and nickel deposits in the region. In addition, one of the largest diamond mines in the world is located at Orapa in the Makgadikgadi, a depression of the northeastern Kalahari. The Kalahari Desert is also one of the most treacherous deserts in the world. While it does not look like a desert, it behaves like one. During the short rainy season it transforms into a great paradise of lush vegetation and a colorful and lively fauna. However, the moment the rains are gone the Kalahari becomes dry and moody. It can rain very heavily in one day, rain that produces floods that sweep everything while the next day can be as dry as ever.
Above everything else, Kalahari is a place of mystery, with legends and tales that go far into the past when the great tribe of the Bushmen lived undisturbed and free. Kalahari is Bushmen's last place to survive in a world that constrained them to this last territory. The mystery of the Kalahari brings in another aspect of the beauty of this desert; spotted with giant Baobabs, acacia trees and tall grass. The desert is part of the huge sand basin that reaches from the Orange River up to Angola, in the west to Namibia and in the east to Zimbabwe.
The sand masses were created by the erosion of soft stone formations. The wind shaped the longish sand ridges, which are so typical of the landscape of the Kalahari. Only in recent geological history, 10 to 20,000 years ago, were the dunes stabilized through vegetation, so the area should actually be called a dry savannah. Unlike the dunes of the Nimbi Desert, those of the Kalahari are not wandering. The dominant vegetation: grasses, thorny shrubs and Acacia trees, can survive long drought periods of more than ten months every year. The remarkable nests of the weaver bird are frequently seen in the camel thorn and other acacia trees. These inconspicuous little birds, which resemble sparrows, live in huge communal nests with a diameter of up to two meters. At any given time, hundreds of lively little birds are breeding and feeding their youngsters in such a nesting colony.
The Kalahari Desert is not really a desert, but rather a large arid to semi-arid sandy area in southern Africa, covering much of Botswana and parts of Namibia and South Africa. Though it is semi-desert, it has huge tracts of excellent grazing after good rains and is rich in wildlife. The homeland of the Bushmen for perhaps thirty thousand years, the desert was the setting for the movie The Gods Must Be Crazy, which featured a Bushman family.
A strange, yet essential feature of this region are the pans, which are shallow hollows consisting of hard, gray clay. While appearing drab and flat, these pans provide essential salt for the animals of the Kalahari. They vary in size from a few hundred meters to a few square kilometers. There are two other distinct ecosystems found in the central Kalahari region: rich savanna and grasslands.
The core area of the desert covers an area of 100,000 square miles (260,000 square kilometers). But the surrounding Kalahari Basin covers over 2.5 million square kilometers, extending farther 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 northwest Botswana, forming marshes that draw abundant wildlife. Ancient dry riverbeds—called omuramba—traverse the central northern reaches of the Kalahari and provide standing pools of water during the rainy season. Previously havens for wild animals from elephants to giraffes, and for predators such as lions and cheetahs, the riverbeds are now mostly grazing spots, though leopards or cheetahs can still be found.