Inland waters of Africa
In terms of total annual flow (cubic 5390 km) Africa is behind Asia and South America. Pools area, length, volume of flow, many rivers are among the largest in the world (Nile, Congo). The distribution of the river network and runoff throughout the continent extremely evenly, that depends mainly on differences in climatic conditions, topography and nature of the rocks of certain areas. Along with areas with dense hydrographic network and large lakes, vast spaces of Africa or almost completely deprived local river network. Many rivers do not reach the ocean and end up in landlocked endorheic basins. Almost all the rivers of the continent are fed by rain. Only in the deserts and semi-deserts diet of their soil, and the high peaks of the Atlas mountains and Eastern Africa the sources of the rivers are fed as melt water of snow and glaciers.
The longest river of Africa – Nile (6671 km) at the same time and the longest river of the Earth. The area of the basin of the Nile – 2870 thousand sq. km. the source of the Nile – the river Rukarara in the system of the Kagera river, originating at an altitude of 2000 m. In the next part – between lakes Victoria and albert (Mobutu-CECE-Seko) the river is called Victoria Nile. After crossing lake albert, the river receives the name of the albert Nile. In the upper course, the river flows into the bottom of the gorge, forming rapids and waterfalls. Leaving the valley, it flows slowly and peacefully and it is called the White Nile. At Khartoum the White Nile meets its largest tributary-the Blue Nile flowing from the Ethiopian highlands. After the merger of White and Blue Nile the river becomes twice wider and receives the name of Neal.
Nile crosses the Sahara, having no tributaries here, and when entering the Mediterranean sea forms a Delta. The river has great importance for North-Eastern Africa (Egypt, Sudan). On both banks of the Nile almost stretches across the entire Sahara oasis with fertile Nile water irrigated lands. In ancient times the Nile annually overflowed, bringing on the fields of Ancient Egypt of the fertile silt. After the construction of hydroelectric power station in Aswan and lake Nasser, the river was regulated, the Nile floods ceased.
The deepest and the second longest river in Africa – Congo (Zaire) (4320 km). The high-water and a basin area it is second only to the Amazon. The river in two places crosses the equator and flowing year round. The Congo flows through the ledges of plateaus, so on the river there are many rapids and waterfalls. Major tributaries of the Congo – Lukuga, the Ubangi, Kasai. The Congo empties into the Atlantic ocean. Huge masses of river water desalinate the ocean at a distance of several tens of kilometers. The huge amount of runoff is determined by the Equatorial position of the basin and that the river receives tributaries from the Northern and southern hemispheres, in which the maximum discharge occurs at different times of the year.
The third length and the basin area of Africa – Niger. In the middle reaches of this plain, the river, and in upstream and downstream in its bed many rapids and waterfalls. On a considerable part of its course the river crosses the dry areas, so it is of great importance for irrigation. this purpose built dams and irrigation canals.
Zambezi – the largest of the rivers of Africa flowing into the Indian ocean. Her length – 2660 km away and the largest waterfall on the Zambezi and one of the largest in the world – Victoria ’ s has a height of 120 m and a width of 1800 m. Water cast, raises hundreds of meters up great columns of tiny splashes.
Almost all major lakes of Africa lie in tectonic depressions of the East African plateau They are framed by steep slopes and large depth. Lake Tanganyika in depth second after oz. Baikal (area – 34 sq km, depth of – 1470 m). Lake Victoria the biggest in Africa and second largest freshwater lake in the world. Its area is 68 thousand sq. km. it is located in a tectonic trough of the East African platform, and is not in a tectonic break. The lake is shallow, average depth of 40 m, has a rounded shape, a flat, sandy, often swampy shores. In the rest of Africa, lakes are few. They mostly occupy the low places are inland depressions. For example, lake Chad, fed by rivers, depth of 4-11 m, the area in the dry season about 10 thousand square km, but after the floods it rises to 26 thousand sq. km In arid and desert areas have dried-up lake, covered with crusts of salt. A thin layer of saline water appears in them only after the infrequent rains.
In those parts of Africa where rainfall is not enough, the internal waters used for irrigation. The river also is rich in hydropower, particularly large reserves in the Congo basin. Many rivers and lakes serve as water ways. In them is found in abundance in fish, which is of great importance in the diet of Africans.