Botswana and 30°E. The country is predominantly flat, tending toward gently rolling tableland. Botswana is dominated by the Kalahari Desert, which covers up to 70% of its land surface. The Okavango Delta, one of the world's largest inland deltas, is in the northwest. The Makgadikgadi Pan, a large salt pan, lies in the north. The Limpopo River Basin, the major landform of all of southern Africa, lies partly in Botswana, with the basins of its tributaries, the Notwane, Bonwapitse, Mahalapye, Lotsane, Motloutse and the Shashe, located in the eastern part of the country. The Notwane provides water to the capital through
Kalahari Desert Kalahari, except on salt pans during the dry season, the vegetation cover can be clearly denser, up to almost 100% in some limited areas. In an area of about 600,000 km in the south and west of the Kalahari, the vegetation is mainly xeric savanna. This area is the ecoregion identified by World Wide Fund for Nature as Kalahari xeric savanna AT1309. Typical savanna grasses include ("Schmidtia", "Stipagrostis", "Aristida", and "Eragrostis") interspersed with trees such as camelthorn ("Acacia erioloba"), grey camelthorn ("Acacia haematoxylon"), shepherd’s tree ("Boscia albitrunca"), blackthorn ("Acacia mellifera"), and silver cluster-leaf ("Terminalia sericea"). In certain areas where the