The geology of the area, a part of the African Rift Valley System, has resulted in the ‘capture’ of the Okavango River that has formed the Delta and its extensive waterways, swamps, flooded grasslands and floodplains. The Okavango River, at 1,500kms, is the third largest in southern Africa. The Delta’s dynamic geomorphological history has a major effect on the hydrology, determining water flow direction, inundation and dehydration of large areas within the Delta system. The site is an outstanding example of the interplay between climatic, geomorphological, hydrological, and biological processes that drive and shape the system and of the manner in which the Okavango Delta’s plants and animals have adapted their lifecycles to the annual cycle of rains and flooding. Subsurface precipitation of calcite and amorphous silica is an important process in creating islands and habitat gradients that support diverse terrestrial and aquatic biota within a wide range of ecological niches.
Permanent crystal clear waters and dissolved nutrients transform the otherwise dry Kalahari Desert habitat into a scenic landscape of exceptional and rare beauty, and sustain an ecosystem of remarkable habitat and species diversity, thereby maintaining its ecological resilience and amazing natural phenomena. The annual flood-tide, which pulses through the wetland system every year, revitalizes ecosystems and is a critical life-force during the peak of the Botswana’s dry season (June/July). The Okavango Delta World Heritage property displays an extraordinary juxtaposition of a vibrant wetland in an arid landscape and the miraculous transformation of huge sandy, dry and brown depressions by winter season floods triggers spectacular wildlife displays: large herds of African Elephant, Buffalo, Red Lechwe, Zebra and other large animals splashing, playing, and drinking the clear waters of the Okavango having survived the dry autumn season or their weeks’ long migration across the Kalahari Desert.
Courtesy of UNESCO