African Geograpahy – Hydrology

 

In order to sustain the ample life forms that have occupied Africa since the very beginning of human civilisation, 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.

Image of Aerial view of the Victoria Falls on the border of Zambia and Zimbabwe.
Aerial view of the Victoria Falls on the border of Zambia and Zimbabwe.

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.

Effects Of Climatic And Environmental Changes On Ancient African Civilisations


Hundreds of thousands of years ago, the entire planet earth looked very different to what modern man experiences today. Continents were not yet divided, and the vegetation and animals were different. Significantly, the climate was also vastly different to what it is today. Climate plays an integral role in determining the plants and animal that live in a certain areas, as well as how habitable a place is for human beings.

In fact, even the theory of the evolution of man was dependent largely on the climatic influences on our ancient ancestors. It is hypothesised that the ancient versions of man were forced to walk upright, lose body hair and develop their coordination for survival in a changing environment. New skills also needed to be learned as farming techniques and living habits had to be adapted.

Ancient Africa experienced major vacillations between mega-droughts and Ice Ages, although these fluctuations occurred over thousands and thousands of years. As humans continued to develop and evolve through these phases, they needed to make major adaptations, not only to their ways of life, but also to their personal body structure. Prior to 135 000 years ago, the whole of Africa was lush and fertile, with a tropical climate. Then, the most intense mega-drought ever to occur hit the continent in the period referred to as the early part of the Late Pleistocene epoch. This is believed to have led to the migration of most of our human ancestors into other areas that were more habitable and fertile. Lake Malawi has been used by scientists as a rain gauge to ascertain water levels in ancient times. Research has shown that, during this mega-drought, the lake’s level dropped at least 1968 feet, or 600 metres! Evolutionists claim that this severe lack of water not only pushed ancient man from the area, it also forced aquatic animals (such as fish) to develop the facilities to be able to survive on dry land, thus evolving into land animals.

As people flocked out of the continent, only a very small proportion of this specific generation remained. Humankind as we know it is widely believed to have come from these few remaining on the continent, who evolved significantly and in response to the climatic changes.

These conditions continued until about 70 000 years ago, when the climate was again characterised by wetter conditions. These led to the growth and renewal of fresh vegetation, as well as an increased water supply to the region. More people were in the area during this time of abundance, and the population grew. This increase in numbers eventually led to migrations due to space limitations and the ownership of land.

Then, about 20 000 years ago, an Ice Age overcame the entire earth. This meant that the planet underwent a long-term period of cold temperatures over most of its surface. In places like North America and Eurasia, giant ice sheets covered enormous proportions of the land, making it impossible to farm and, sometimes, even live in these areas. This final Ice Age lasted for about 9 500 years. It forced most of the populations to migrate to the highlands, where they would be relatively protected from the ice sheets. Again, these civilisations had to adapt their farming methods, and change their diet, social habits, clothing and migratory patterns. This forced an evolution to a certain extent. Body hair was necessary to keep people warm, their skin lightened due to a lack of the harsh rays of the sun that they experienced during the mega-droughts, etc…

When this Ice Age came to an end 10 500 years ago, areas like the Sahara were left fertile and healthy. This made it and the other areas like it the ideal spots in which to settle as ancient man began to descend from the highlands. Animals and plants thrived in this environment, which made it very desirable in the eyes of mankind. The abundance of food, water and sunshine again changed the habits and physical structures of our earliest forefathers.

These conditions lasted for some time, but the Sahara in particular continued to experience fluctuations between humid and dry conditions. These eventually left the entire area unable to yield crops or sustain life for any extended period of time. Today, it remains a large stretch of desert. Then, approximately 2500 years ago, the group of people who had made their home in the Sahara began to follow the direction of the Nile River, which held promise of a rich water supply. The arid conditions of the Sahara and its surrounds continue to the present day.

Africa has, since prehistoric times, proven to be a place of fascination, life and evolution. Changes in the climate were often dramatic, and these were, to a great extent, responsible for determining the ancient civilisations that inhabited this vast continent. It is no wonder that many researchers and scientists maintain that Africa is the Cradle of Mankind, and research continues to yield fascinating evidence of this theory.