Okavango Delta Basics

Okavango Delta Basics

The Okavango Delta is a unique ecosystem of papyrus-lined waterways, knee-deep floodplains, water-lily lagoons, shady forest glades and rich savannah grasslands.

The Okavango river is southern Africa's third largest watercourse. It originates in the uplands of Angola and flows across the Namibia's Caprivi strip into Botswana. It is here that it spreads out over the Kalahari sandveld in an immense, fan-shaped inland delta. This delta, it is in fact an alluvial fan of sediment and debris, which filled a trough formed by the sinking of the earth's crust, between a series of parallel faults across the Okavango River.

History

Millions of years ago the Okavango river use to flow into a large inland lake called Lake Makgadikgadi (now Makgadikgadi Pans). Tectonic activity and faulting interrupted the flow of the river causing it to backup and form what is now the Okavango delta. This has created a unique system of water ways that now supports a vast array of animal and plant life that would have otherwise been a dry Kalahari savanna.

The Source

The Delta is fed by the Okavango River originating over 800 miles (1,280 km) away in the highlands of Angola. The Angolan highlands have an average rainfall of between 1,200 and 2,000mm per year, compared to around 400-600mm in the Okavango. The Angolan rains start in October and finish sometime in April. The floods only cross the border between Botswana and Namibia in December and will only reach the bottom end of the delta sometime in July.

Taking almost nine months from the source to the bottom. This slow meandering pace of the flood is due to the lack of drop in elevation, which drops a little more than 60 metres over a distance of 450 kilometres. The delta's water deadends in the Kalahari - via the Botetle river, with over 95 per cent of the water eventually evaporating.

During the peak of the flooding the delta's area can expand to over 16,000 square kilometres, shrinking to less than 9,000 square kilometres in the low period. As the water travels through the delta, the wildlife starts to move back into the region. The areas surrounding the delta are beginning to try out (the rains in Botswana occur approximately the same time as in Angola) and the wildlife starts to congregate on the edge of the newly flooded areas, May through October.

Wildlife

The delta environment has large numbers of animal populations that are otherwise rare, such as crocodile, red lechwe, sitatunga, elephant, wild dogs, buffalo, wattled crane as well as the other more common mammals and bird life.