OKAVANGO DELTA July 12th, 2013
ABOUT THE OKAVANGO DELTA
The Okavango Delta, also called the Okavango Swamp, is a large inland delta in Botswana, formed where the Okavango River reaches a tectonic trough in the central part of the endorheic basin of the Kalahari. All the water reaching the Delta is eventually evaporated and transpired, and does not flow into any sea or ocean. Each year around 11 cubic kilometres of water spreads over the 6,000-15,000 km² area. The Moremi Game Reserve, a National Park in Botswana, is on the eastern side of the Delta. This statistical importance helped the Okavango Delta secure a position as one of the Seven Natural Wonders of Africa.
The Okavango is produced by seasonal flooding. The Okavango River drains the summer (January–February) rainfall from the Angola highlands and the surge flows 1,200 kilometres in about one month. The waters then spread over the 250 km by 150 km area of the delta over the next four months (March–June). The extraordinarily high temperature of the delta causes rapid transpiration and evaporation, causing a cycle of rising and falling water level.
The Okavango Delta's abundant vegetation is an oasis in an arid country. The average annual rainfall is 450mm and most of it falls between December and March in the form of heavy afternoon thunderstorms.
There are three main geographical areas in the Okavango Delta:
- the Panhandle
- the Delta
- dryland
The Panhandle begins at the Okavango’s northern reaches, at Mohembo, extending down for approximately 80 kilometres. Its corridor-like shape is contained within two parallel faults in the Earth’s crust. Here the river runs deep and wide and the swamps are perennially flooded. The dominant vegetation is vast papyrus beds and large stands of phoenix palms. The main tourist attractions of the Panhandle are fishing, birding and visiting the colourful villages that line its western fringes.
At Seronga, the fan-shaped Delta emerges, and the waters spill over the Delta, rejuvenating the landscape and creating stunning mosaics of channels, lagoons, ox-bow lakes, flooded grasslands and thousands upon thousands of islands of an endless variety of shapes and sizes. Many of the smaller islands are grandiose termitaria built by fungus-growing termites, one of 400 termite species in Africa, whose fantastic structures are a source of refuge and food for many animals.
The Delta region of the Okavango can vary in size from 15 000 square kilometres during drier periods to a staggering 22 000 square kilometres during wetter periods. Its dominant plant species are reeds, mokolwane palms, acacia, sycamore fig, sausage trees, raintrees and African mangosteen.
At it's lower reaches, the perennial swamps give way to seasonal swamps and flooded grasslands. To the southeast the third vegetation region becomes evident, as it changes to true dryland. There are three major land masses here: the Matsebi Ridge, Chief’s Island and the Moremi tongue. Here the vegetation is predominantly mophane, acacia and scrub bush and the land is dotted with pans. It is to this region that large numbers of mammals retreat during the dry winter months.
WILDLIFE IN THE OKAVANGO DELTA
The Okavango delta is both a permanent and seasonal home to an extensive variety of wildlife. Major species to be seen include elephant, giraffe, zebra, hippo, crocodile, rhino, waterbuck, cheetah, leopard, sable, reedbuck and impala. The Okavango Delta is also home to many fish species including Tigerfish, Tilapia and Catfish. The same species are to be found in the Zambezi River, indicating a historic link between the two river systems. There is also an immense variety of birds in the Okavango Delta- land and water, resident and migratory, some of which are rare and endangered.
Papyrus and reed rafts make up a large part of the Okavango's vegetation. During the flood season they float above the sandy river bed with roots dangling free in the water. This gap between bed and roots is utilised as shelter by crocodiles. The plants of the Delta play an important role in providing cohesion for the sand.
PEOPLE
People living in the Okavango Delta comprise of five ethnic groups, each with its own ethnic identity and language, namely Hambukushu, Dceriku, Wayeyi, Bugakhwe and ||anikhwe.
The Okavango Delta has been under the political control of the Batawana (a Tswana sub-tribe) since the late 18th century. Most Batawana, however, have traditionally lived on the edges of the Delta. Small numbers of people from other ethnic groups such as Ovaherero and Ovambanderu now live in the Okavango Delta, but since the majority of the members of those groups live elsewhere and the habitation is recent they are not considered as part of the Okavango Delta peoples. There are also several Bushmen groups represented by a handful of people. These groups were decimated by diseases of contact in the middle part of the 20th century, and most of the remaining members have intermarried with the ||anikwhe.
THREATS TO THE OKAVANGO DELTA
The Namibian government has presented plans to build a hydropower station in the Caprivi Region, which would regulate the Okavango's flow to some extent. While proponents argue that the effect would be minimal, environmentalists argue that this project could destroy most of the rich animal and plant life in the Delta. Other threats include local human violation and intrusion as well as regional extraction of water in both Angola and Namibia.
ACTIVITIES/ ATTRACTIONS IN THE OKAVANGO DELTA
Major tourist attractions in the Delta and the dryland areas are game viewing, bird watching and boating, often in the traditional mokoro. The diversity and numbers of animals and birds can be staggering. A recent overview of the Okavango records 122 species of mammals, 71 species of fish, 444 species of birds, 64 species of reptiles and 1300 species of flowering plants. A successful rhino reintroduction programme in the Okavango now puts the population of White Rhino at approximately 35, and Black Rhino at 4.
Other things to do include game drives, safari walks, boat cruises, elephant back safari and horse riding. It should be noted, however, that game viewing very much depends on season, and water and food availability.