Sahara Desert Tablelands

Ergs

These are huge sand dunes that can rise to heights of more than 300 m. Ergs naturally contain large quantities of salt.

Regs

These are plains of sand and gravel that cover over 70 per cent of the Sahara. Regs are waterless remains of prehistoric sea beds.

Hamadas

These are elevated plateaus that can reach heights up to 3,353 m. Along with Ethiopian Highlands, other mountains include in this category are Tibesti Mountain and the Ahaggar Mountains.

The Sahel

It is a narrow band of flat, semi-arid and barren land. The Sahel forms a transition zone between the Sahara Desert in the north and the Savannahs in the south. It stretches up to roughly 5,400 km, from Senegal in the west to Sudan in the east. The land within the Sahel has been drained

These are the vast, undulating plains covering up to an area of 30,000 km2.

The Great Rift Valley

The tablelands in Africa cover a major part of the continent. These are mainly of volcanic origin and are composed of old hard rocks. The tablelands are generally divided between the North-Western Plateau and the South-Eastern Plateaus.

The Great Rift Valley is a special physical feature of the Southern Plateau. It is a long narrow valley, formed nearly 25 million years ago. It consists of vertical cracks developed because of the movements within the Earth. The valley stretches for a distance of 5,000 km and extends from the Lake Malawi to the Red Sea and from Gulf of Aqaba to the Dead Sea in Jorden. The valley continues through the Ethiopian Highlands by cutting across it.

The Great Rift Valley shows the presence of many freshwater lakes such as Malawi, Tanganyika and Turkana.

High Plateau

In the south, the High Plateau exists as divided into three different plateaus. These include the Ethiopian or Abyssinian Plateau, the Central lake Plateau and the South African Plateau. The High Plateau ends in the south with the Drakensberg Mountains, which form the high, eastern edge of the

In the lower courses, however, these rivers descend into the coastal plains. Presence of numerous rapids and waterfalls has made river navigation difficult, in these regions.

River Nile is the world’s longest river. It flows northwards from the East-Central Africa to the Mediterranean Sea. Lake Victoria acts as one of the major sources of river Nile. As the lake is located in the rainy equatorial region, the river Nile shows water discharge throughout the year.

Zaire and Niger are two of the major rivers in the African continent. These rivers empty into the Atlantic Ocean, similar to the river Senegal flowing through Northern Africa. The rivers Limpopo and Zambezi flow into the Indian Ocean, as the River Chari empties into the Lake Chad, forming an inland drainage area.

River Okavango is another important river that flows through the Namib Desert. It is Fed by rains in the mountains of Angola. The river is perennial and passes through tropical forests on its course.

The River Congo is Africa’s second longest river. It discharges more water than the river Nile and is the deepest river in the world. The Congo River flows westwards through the Central