The Kavango Basin is the fourth largest international river basin in southern Africa, and the Kavango is the largest river in the region that does not empty out into an ocean. Estimates of the Kavango Basin area range from 320,000 (Stanley Consultants 1995:2-13) to 570,000 sq km (Pallett 1997:73) and 586,000 to 721,277 sq km (World Resources Institute and Worldwatch Institute 1998:2-26). The main river in the catchment is the Kavango, or, as it is called in Angola, the Rio Cubango.