Hydrology

In order to sustain the ample life forms that have occupied Africa since the very beginning of human civilization, a sufficient supply of clean, fresh water was required. Later, when trade with other lands began, water routes across rivers and even oceans were a must.

The African continent is rich in rivers, from the short ones that run into longer ones to the immense water systems that flow into the oceans. Some of the most expansive rivers run from the African highlands in the interior to the coast. Most of the drainage in Africa is in the north and west, meaning that most rivers run into the Atlantic Ocean.

The Nile is the longest river in Africa, followed by the Congo River. Both of these are situated in the East Africa plateau. Lake Victoria is Africa’s largest lake. This is fed by smaller streams, as are lakes Edward and Albert. Lake Victoria and Edward in turn, flow into Lake Albert. It is from here that the Nile acquires its supply of water, along with other sources such as the Blue Nile and Sobat, as it courses through a large portion of Africa before flowing into the Mediterranean.

The Chambezi River flows into the Bangweulu River and, from there, the Congo River emanates. The Congo’s course changes from south to north at Lake Mweru, from where it twists and turns through west equatorial Africa, turning towards the southwest and into the Atlantic Ocean. The Congo basin in which the river is situated is only smaller than the entire Amazon River.

The Niger is Africa’s third largest river and is situated in West Africa. This river too changes direction and flows into the Atlantic Ocean. This did not make sense to early explorers and geographers, and remained a mystery for hundreds of years.

The Orange River in South Africa is fed by the drainage from the magnificent Drakensberg mountain range. This is remarkable, particularly because they are on opposite sides of Africa. Another significant South African river is the Limpopo. This is responsible for the drainage of a part of the interior plateau.

The Zambezi River is the only river that flows into the Indian Ocean that is significant in terms of the drainage of large interior plateaus. Although its initial course veers to the south and west, it eventually heads east. It is in this vicinity that the strip of higher ground cuts through the African continent and water from this source flows into the Zambezi. Another water source for this great river is the Taukhe. Along with many swamps and lakes, water from this river frequently overflows into the Zambezi, to end up in the Indian Ocean.

The East African highlands are partly drained by the Rovuma, Rufiji, Tana, Jubba and Webi Shebeli, while water from the Ethiopian mountains is transported by the Hawash, which ends in the Gulf of Aden. In the centre of the East African plateau is an inland drainage system, which leads water into the Great Rift Valley’s lakes.

Some researchers believe Lake Tanganyika to have been an arm of the sea when the Congo basin was still submerged. This is largely because of the marine life found in the lake, including jellyfish, prawns and crabs.

Many of these lakes and rivers are relatively shallow, meaning that dry seasons often leave them parched and muddy. They are also easily navigable, even when full of water. This enabled and encouraged ancient Africans and the explorers entering the continent to travel along them and discover otherwise remote areas and isolated societies.