THE OKAVANGO DELTA
Bush Ways Safaris visits the Okavango Delta in two main areas.
The Thaoge Channel and Flats in the North West, where we do our Mokoro adventures, and Moremi Game Reserve where we explore the eastern Islands of the Okavango Delta by Safari Vehicle searching the plains and riverine forests for the multitude of wild animals that occur in this natural paradise.
The Thaoge Channel and Flats are the Okavango Delta as we imagine it, endless lagoons covered in water lilies and bordered by lush little palm islands. Here we search for an island where we set up camp to explore the surrounding area on foot, watch the sunset on a lagoon from our Mokoros, listen to our Bayei Mokoro polers singing in the African night.
Moremi Game Reserve encompasses the eastern extremities of the Moanachira channel and almost the entire Khwai river which dies in the Kalahari sands a few kilometres from the border of Moremi. This intrusion of water into the otherwise barren Kalahari sands result in an ecological richness and diversity rarely found in nature.
The Okavango Delta must truly be one of Africa's most enchanted places. A swirl of lushness in a desert of Kalahari sand, the Delta is a remarkable phenomenon. It owes its origins to the formation of the rift valley across the course of the Okavango River. The area was formed over the last 5 million years due to atmospheric changes and movement of the Earth's crust.
About 5 million years ago, a relatively recent event (geologically speaking) the southern hemisphere's atmosphere became increasingly dry due to the glaciation of Antarctica, which absorbed most of the atmospheric moisture. 3 million years ago, strong easterly winds caused the formation of elongated dunes that run from east to west across the middle Kalahari. When wetter times returned these dunes channelled the flow of the rivers in one direction, into Lake Makgadikgadi. These wetter times also caused the great rivers of the middle Kalahari to flow, namely the Okavango, Chobe, and Zambezi Rivers. They all travelled eastwards with the Limpopo River into the Indian Ocean.
Then about 2 million years ago, a geological upheaval of the Earth's crust caused the formation of a fault, which changed the flow of these great rivers. This is known as the Kalahari-Zimbabwe axis and runs from Harare, through Bulawayo, and ends in the eastern side of the Kalahari. This caused the rivers to flow into and fill up the large basin that was formed, creating one of the greatest lakes in Africa - Lake Makgadikgadi.
Eventually the lake was filled to capacity and the water had to find a way to the ocean. Therefore, about 20 000 years ago the waters of this great lake were forced northwards and then eastwards. This caused the middle and lower Zambezi to connect, which resulted in the formation of Victoria Falls. With the water now able to flow out of the lake, a partial draining of the lake occurred. A drier climatic period followed which caused an increase in evaporation and a decrease in the river flow. By about 10 000 years ago the drying of the Makgadikgadi Lake was in an advanced stage. Windblown sand, as well as the Okavango River depositing increasing amounts of sediment and debris in the lake, were gradually filling the lake.
The formation of the Gumare fault caused a reduction in the elevation of the land, thus causing the water of the Okavango River to spread out over a much larger area of land and forming the now characteristic fan-shaped inland delta of the Okavango. Today the only remains of the Ancient Lake Makgadikgadi (apart from the Okavango Delta) are Nxai Pan, Lake Ngami, Lake Xau, the Mababe Depression, and the two main pans of Makgadikgadi (Sua and Ntwetwe Pans).
A characteristic of the Delta is its annual flood. The Okavango River, which rises in Angola on the Benguela Plateau, flows southeastward across the Caprivi Strip in Namibia, tumbles through the Popa Falls Rapids, and enters Botswana at Mohembo. Bringing the result of heavy rains in Angola to Botswana (an estimated 11 billion cubic meters of water every year). The swollen river breaches its low-water banks and begins the annual inundation of its floodplains. No two floods are ever the same, but one can say that the permanent Delta is some 16 000 square kilometres in extent, whilst a big flood may seasonally cover as much as 18 000 square kilometres. It can take 6 months to work its way from Mohembo, through the labyrinth of channels and lagoons to reach Maun.
More than 95% of the Okavango's water evaporates before it reaches the Thamalakane River near Maun. The Thamalakane River drains the area and leads the remainder of the water to the Boteti River, which flows through a break in the fault to Lake Xau and eventually the Makgadikgadi Pans. This outflow of water is one of the reason's why the water in the Delta is fresh since it carries away the salts. The flooding of the Okavango is not a violent process. The waters spread gently down the channels and across the plains. The total fall in height from one end of the delta to the other is only 62 meters and that over a distance of some 250 kilometres! The slow movement of water means a low sediment load and hence the incredible clarity and purity of the Okavango's water, for which it is justly renowned.
Unique as one of the world's few inland deltas, the Okavango Delta adds enormously to the variety of experiences open to the visitor. An obvious attraction is the spectacular game viewing; among the best in the world and certainly situated in the most unspoilt corner of Africa. Herds of elephants can be seen here, as well as all the main cats, hyenas, wild dogs and many antelope, including the rare and shy sitatunga. Not only the wildlife but also the vegetation makes for an interesting visit.
The only vegetation types that can survive in such a unique system are reeds and papyrus. Reeds (Phragmites australis and P. mauritiarius) grow in the water of medium depth and are rooted. Papyrus (Cyperus papyrus) on the other hand, floats and bends easily with the current. Papyrus is mainly eaten by Sitatunga.
Other interesting plants include
The underwater plants such as Bladderworts (Utricularia spp.) and Water Chestnuts (Trapa natans), as well as; - The floating plants such as Water Lilies (Nymphaea caerulea). A tree species common only to the perennial swamp and not to the seasonal swamp is the Delta Palm (Phoenix reclinata).
Other delta experiences open to the visitor are
Take to the waters of this magic world of islands and lagoons by dugout canoe (mokoro) and, or power boat. - Aircraft offer flights over the delta, which provides an excellent opportunity to view the delta system as a whole unit. A very memorable experience!