OKAVANGO RIVER

also called Kubango River, fourth longest river system in southern Africa, running basically southeastward for 1,000 miles (1,600 km) from central Angola, where it is known as the Kubango, to the Kalahari (desert) in northern Botswana, where the river terminates in an immense inland delta known as the Okavango Swamp. The riverformerly sometimes called the Okovangotakes its name from the Okavango (Kavango) people of northern Namibia. David Livingstone, the Scottish missionary and explorer, and the first European known to have seen the Okavango, reached its swampy delta in 1849. The Okavango River rises as the Kubango just south of Vila Nova, Angola, on the Bi Plateau, at an elevation of 5,840 feet (1,780 m). It flows south and then southeastward through Angola in a course that is initially broken by rapids. Along its middle course the Okavango forms part of the Angola-Namibia border. After being joined by its largest tributary, the Kwito River, the Okavango River then crosses Namibia's narrow Caprivi Strip to enter Botswana. Soon after entering Botswana the Okavango begins to widen as it enters the flat, swampy tract in which it terminates. About 70 miles inside Botswana, the river spreads out to form a triangular-shaped delta, the base of which extends for about 150 miles (240 km). This delta region, less than half of which is swamp year-round, covers an area of about 6,500 square miles (16,800 square km). Most of the delta's area is inundated during the rainy season. The river is subject to drastic changes in flow along its length because of seasonal variations, the reception of tributaries, evaporation, and absorption into the riverbed. In its uppermost course, the Okavango flows through woodland country that becomes less densely forested as the river progresses southward. Further to the southeast, the river passes through areas occupied by dry savanna, i.e., grassland with scattered acacia trees. In the Okavango Swamp itself, the vegetation falls into two main typesdense clumps of papyrus reeds and other aquatic plants in the river and floodplain channels; and patches of woodland and savanna occupying the slightly higher parts of the delta. In the delta the dense growth of papyrus reeds is continually blocking the river's channels, thus changing the pattern of flow. Although the Okavango brings water to a parched land, the river's resources remain largely unused, and its banks are only sparsely settled. Except for small craft, the Okavango is virtually unnavigable. A major problem for the Tswana (Batswana) people, the main inhabitants of the Okavango delta, has been control of the tsetse fly. The Moremi Wildlife Reserve covers 1,463 sq mi (3,788 sq km) of the northeastern corner of the Okavango Swamp. Its teeming wildlife includes lions, cheetahs, buffalo, wildebeests, hippopotamuses, zebras, wild dogs, crocodiles, and other species. Birds include storks, ibis, herons, egrets, cranes, and weaver birds. There are also numbers of ducks, geese, and quail. Varieties of fish include bream, pike, barbels, and tiger fish.