UNESCO World Heritage Site | |
---|---|
Location | Botswana |
Criteria | Natural: vii, ix, x |
Reference | 1432 |
Inscription | 2014 (38th Session) |
Area | 2,023,590 ha |
Buffer zone | 2,286,630 ha |
Coordinates | 19°24′S 22°54′E / 19.400°S 22.900°E |
Official name | Okavango Delta System |
Designated | 12 September 1996 |
Reference no. | 879[1] |
The Okavango Delta[2] (or Okavango Grassland; formerly spelled "Okovango" or "Okovanggo") in Botswana is a vast inland delta formed where the Okavango River reaches a tectonic trough at an altitude of 930–1,000 m[3] in the central part of the endorheic basin of the Kalahari.
It is a UNESCO World Heritage Site as one of the few interior delta systems that do not flow into a sea or ocean, with a wetland system that is largely intact.[4] All the water reaching the delta is ultimately evaporated and transpired. Each year, about 11 cubic kilometres (2.6 cu mi) of water spreads over the 6,000–15,000 km2 (2,300–5,800 sq mi) area. Some flood waters drain into Lake Ngami.[5] The area was once part of Lake Makgadikgadi, an ancient lake that had mostly dried up by the early Holocene.[6]
The Moremi Game Reserve is on the eastern side of the delta. The delta was named one of the Seven Natural Wonders of Africa, which were officially declared on 11 February 2013 in Arusha, Tanzania.[7] On 22 June 2014, the Okavango Delta became the 1000th site to be officially inscribed on the UNESCO World Heritage List.[8][4]
The total drop in altitude between Mohembo and Maun, a distance of440 km, is only 62 metres, giving a gradient of approximately 1:7,000 only
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