The Chad Basin, or Lake Chad Basin, is a large lowland area of central Africa. It has a long history of human settlement and, for a long time, it was an important crossroads for trans-Saharan trade. The most significant feature inside the basin is Lake Chad, which has been known outside Africa since the middle Ages, It is endorheic as none of its water flows into an ocean. The region has played an important role in the development of cultures and history in northern and central Africa and has become a rich and promising area of research for social scientists. Lake Chad has contributed to the development of peoples, flora, and fauna in the region for thousands of years. As a source of water, the region has attracted many immigrants, explorers, and adventurers. The annual fluctuation of the lake's water level and the floods associated with this cyclical change created opportunities for the development of cultures and nations and made the area a place of refuge and protection.
The fresh water Lake Chad is the fourth largest lake in Africa after lakes Victoria, Tanganyika and Nyassa. It covers an area of 25, 000km2 in the 60’s and an altitude of 280m with a depth that does not exceed 4m.
The Chad Basin extends between 6°N and 24°N latitude, and between 8°E and 24°E longitude. It covers an area of approximately 2,434,000 square kilometers (940,000 sq mi), equivalent to 8% of the total area of the African continent.
The Chad Basin is surrounded by high mountain ranges which rise up to the highland of the North Equatorial Plateau (known in some countries as the Asande Barrier). This plateau includes parts of the Adamawa Plateau in the west and the Bongo Massif in the east.
In the east, the Chad Basin extends to the 3,088 meters (10,131 ft) high Jebel Marra in Darfur. In the northeast, the basin—known as the Ennedi Plateau—rises to 1,450 meters (4,760 ft). In the north of the basin are the volcanic Tibesti Mountains, including the 3,415-metre (11,204 ft) Emi Koussi, the highest point of the Sahara. To the west lies the Djado Plateau. The northwest border is marked by the mountains of Tassili n'Ajjer in Algeria, whose highest peak is Jebel Azao at 2,158 meters (7,080 ft). The western boundary is formed by the Aïr Mountains and the Termit Massif in Niger. In the southwestern Chad Basin the Jos Plateau, the Biu Plateau, and the Mandara Mountains mark the geographical boundary. In the center of the Chad Basin is the Bodélé Depression, its deepest part at about 155 meters above sea level. Lake Chad is 275 metres (902 ft) above sea level.
The Basin is shared among Chad, Niger, Nigeria, Cameroon, Central African Republic (CAR), Algeria, Libya, and Sudan. The biggest part of the basin lies in Chad, around 1,123,000 square kilometers (434,000 sq mi) covering the center. The western part, 674,000 square kilometers (260,000 sq mi), is in Niger. In the north and northwest 91,000 square kilometers (35,000 sq mi) are in Algeria and 5,100 square kilometers (2,000 sq mi) in Libya. In the southwest there are 179,000 square kilometers (69,000 sq mi) in Nigeria and 47,400 square kilometers (18,300 sq mi) in Cameroon. The southern part of the basin, 216,000 square kilometers (83,000 sq mi), is in the territory of the Central African Republic, and the eastern part, 97,900 square kilometers (37,800 sq mi), is in Sudan.
When recorded in 2011, the Chad Basin had more than 30 million inhabitants, living by activities like fishing, agriculture, and animal husbandry. The population of the basin was growing at 2.72% per year in 2001, and some administrations expect that in 2020 there will be more than 50 million people living there. People living in the basin are drawn from several ethnic groups and tribes; they include Kanuri, Mobber, Buduma, Hausa, Kanembu, Kotoko, Shuwa Arabs, Haddad, Kuri, Fulani and Manga. Main cities in the basin include; Kano, Maiduguri, Maroua, N’DJamena and Diffa.
Vegetation belts and ecological regions
The Lake Chad Basin contains a variety of habitats, including deserts, shrub steppes, savannahs, forests, lakes, wetlands and mountains. About half of the basin area (the north) is occupied by the Ténéré Desert, Erg du Bilma and Erg du Djourab. To the south of the desert in the belt of Sahel-zone is occupied by thorny scrub savannas and dry savannah. Along the rivers Chari, Logone and Komadougou Yobe find flooding savannas and riparian forests and dry forests in the far south. Along the major river systems are in widespread flooding large wetland areas Sategui-Deressia-, Massénya floodplains in Chad, Grand Yaeres in the border region Cameroon/Chad and Hadejia-Nguru wetlands in Nigeria.