Central Africa

Central Africa, region of Africa that straddles the Equator and is drained largely by the Congo River system. It comprises, according to common definitions, the Republic of the Congo (Brazzaville), the Central African Republic, and the Democratic Republic of the Congo (Kinshasa); Gabon is usually included along with the Central African Republic because of their common historical ties, both of these countries having once been part of French Equatorial Africa. Rwanda and Burundi, although they are located east of the East African Rift System, which forms the eastern divide of the Congo basin, are also often considered part of the region because of their long administrative connections with the former Belgian Congo (now Congo [Kinshasa]). The island republic of São Tomé and Príncipe, off the Atlantic coast of Gabon, is also included in the region.

The landscapes of Central Africa are most often wide plateaus, which are smooth in the central part and etched at the periphery. The interior basin of the Congo River is joined to the Atlantic Ocean by a narrow neck traversing ridges parallel to the coast. The basin contains some marshlands in the region where the Congo, Ubangi, Likouala, and Sangha rivers converge and where Lakes Mai-Ndombe and Tumba are found. Its major part, however, consists of drier surfaces (low plateaus or alluvial terraces).

Higher plateaus, which extend through older sedimentary strata around the centre of the Congo basin, reach an elevation of 2,600 to 3,000 feet (790 to 900 metres) north of Brazzaville and exceed 3,000 feet near the Angolan border to the south. In the north a low divide (2,000–2,300 feet [610–700 metres]) separates the Congo River and its tributaries from the Chad basin. The landscape beyond the divide descends by steps toward Lake Chad. Southwest and south of the Chaillu Massif (3,000–3,300 feet [900–1,005 metres]) in Gabon and Congo (Brazzaville) are ridges, traversed through deep and narrow gorges by the Kouilou and Congo. East of this complex the Congo River has eroded a broad basin, known as Malebo Pool, into the upper sedimentary strata before cutting rapids farther downstream.

The most rugged terrain lies on the eastern fringe of the Congo basin. North of Lake Kivu and of Rwanda, the Virunga volcanoes form an east-west–trending range. The highest point in Central Africa, Margherita Peak (16,795 feet [5,119 metres]), whose summit bears residual features of glaciation, is located on the eastern fringe of the Rift Valley on the border of Congo (Kinshasa) and Uganda.

The Congo River basin is second only to that of the Amazon in rate of flow. In the central part of the basin, the fan of quiet rivers constitutes one of the most attractive networks of navigable waters in the world, but this network is cut off from the Atlantic by a succession of rapids in western Congo (Kinshasa) between Kinshasa and Matadi. Downstream from Matadi the river becomes navigable again before entering its estuary. All the rivers in the region flow down through rapids or waterfalls from the peripheral plateaus to the central basin. The rivers of the western region are navigable for only a few miles from their estuaries, though the Ogooué, in Gabon, which lies in a wider sedimentary coastal basin, is navigable for more than 100 miles (160 km).

Some parts of Central Africa lie within the Chad basin (northern Central African Republic) or the Nile basin (eastern Rwanda and northeastern Burundi, the Western Rift Valley north of the Virunga Mountains). Lava fields from the Virungas have blocked the outlet of an ancient hydrographic network previously oriented to the north. This created Lake Kivu; its waters discharge to the south, through the Ruzizi (Rusizi) River gorge into Lake Tanganyika, one outlet of which links the lake with the Lualaba River and thus the Congo. The volcanic dam also caused a river course reversal in northern Rwanda, generating lakes and marshes.

Central Africa is characterized by hot and wet climates on both sides of the Equator. The equatorial strip that extends from the Atlantic Ocean to the Western Rift Valley is influenced throughout the year by the intertropical convergence zone (ITCZ), resulting in intense, heavy precipitation. The mean annual temperatures in the region vary from 77 to 82 °F (25 to 28 °C), and monthly means vary only a few degrees throughout the year. The diurnal range of about 20 °F (11 °C) always exceeds the range of monthly means. Annual rainfall exceeds 80 inches (2,000 mm) in coastal Gabon, in the centre of the Congo basin, and on the mountain summits bordering the Western Rift Valley. There is no serious dry season, but in the extreme east and west there are two months (July and August) of lower rainfall. North and south of the equatorial strip the dry season increases in severity with latitude. It is driest in the Northern Hemisphere in January (when the area receives dry Saharan air masses) and in the Southern Hemisphere in July; the season lasts nearly seven months in the far northern part of the Central African Republic and in far southern Congo (Kinshasa). Notwithstanding its low latitude and proximity to humid air masses, the coastal region of southwestern Central Africa has an abnormally long dry season with a low annual rainfall because of the presence of a cold marine current (the Benguela Current) along the coast. Highland areas tend to be wetter and cooler.

Equatorial Central Africa is covered by an evergreen forest with an area of almost 400,000 square miles (1,035,920 square km). This rainforest—an exuberant world of high trees, rich in epiphytes and lianas—takes three main forms: permanently wet marshy forests at the confluence of the Ubangi and Congo rivers; gallery forests, which are subject to periodic flooding, along banks and river floodplains; and, most extensive, forests of dry land, either featuring a single dominant species or, more often, harbouring a variety of species (sometimes several hundred per acre). This last type of forest is also found on the eastern slopes of the Congo basin, but it changes to high-altitude life-forms on the highlands of the Western Rift Valley.

The rainforest is surrounded by a patchwork of savannas and other forests. Savannas of poor, permeable sandy soils unevenly strewn with small trees cover the plateau surfaces, whereas subequatorial forests fill the valleys. Large areas of the savanna probably were created by slash-and-burn agricultural techniques, through which the original forest was cleared and the resulting grasslands maintained by periodic bushfires. Savannas also border the cooler and drier Atlantic coast of the two Congo republics, while mangrove thickets stretch along the banks of nearby estuaries, lagoons, and deltas.

Beyond this savanna forest region the most distinctive vegetal formation is the dry tropical forest (called miombo in the southeast). Its trees are smaller and less dense than those of the equatorial forest, and they are deciduous, losing their leaves during the dry season. The dry tropical forest covers the southern Kwango and Katanga (Shaba) plateaus in Congo (Kinshasa) but exists only in shreds north of the Equator, in the Central African Republic. In the far north the thorny steppe is a typical Sahelian landscape.

With its steep gradients over short distances, rainy highlands, and relatively dry bottoms, the Western Rift Valley region is characterized by sharp vegetation contrasts. Central Africa’s most famous national park, Virunga National Park in Congo (Kinshasa), is home to elephants, lions, hippopotamuses, warthogs, forest hogs, okapis, and mountain gorillas on the volcano slopes. Also in the same region is Kahuzi-Biega National Park, which features mountain gorillas. In savanna or wooded savanna regions are Garamba National Park in northeastern Congo, well known for its white rhinoceroses, Upemba National Park in southern Congo, parks in the northern part of the Central African Republic, and Akagera National Park in northeastern Rwanda. Other parks and reserves are located in the equatorial forest in Congo, such as Maiko and Salonga national parks.

National borders have split the territory of many ethnic groups. Twa (Pygmies) are scattered in the forests from Cameroon to the mountains surrounding Lake Kivu. The Fang of Gabon also occupy Equatorial Guinea and southern Cameroon. The Teke are spread throughout Congo (Brazzaville), Gabon, and Congo (Kinshasa). The Kongo inhabit western Congo (Kinshasa), western Congo (Brazzaville), and Angola; the Chokwe and the Lunda occupy Congo (Kinshasa) and Angola. In each country some major groups enjoy a numerically dominant position—for example, the Fang in Gabon and the Mboshi, Teke, and Kongo in Congo (Brazzaville). Burundi and Rwanda contain a Hutu majority, a Tutsi minority, and some Twa (Pygmies). In Congo (Kinshasa) the major groups are the Kongo (southwest), Mongo (central basin), Luba (south-central), Zande and Mangbetu (northeast), and Ngbaka (northwest). In the Central African Republic the Baya, in the west, are the most numerous, but the Banda, in the centre, occupy the largest territory. The islands of the Gulf of Guinea have a mixed population originating from Angola as well as from West and Central Africa because of their history as slave plantations and, later, as plantations with largely forced labour.

Most languages spoken in Central Africa belong to the Bantu group of the Niger-Congo language family. In northern Central Africa, Adamawa-Eastern and Sudanic languages are also spoken. The area’s rich linguistic diversity includes the use of lingua francas born of local languages, pidgin creoles (in the islands of the Gulf of Guinea), and European languages, which are the official languages of the various countries (Portuguese in São Tomé and Príncipe, French elsewhere). These lingua francas often overlap borders. Lingala, which is important in Congo (Kinshasa), is also spoken in Congo (Brazzaville), as are Kongo and Sango, which in turn is the main language in the Central African Republic. Swahili, the eastern Africa language, is the lingua franca in eastern Congo (Kinshasa) and among the merchants of Burundi and Rwanda. In the latter countries Rundi and Rwanda are (along with French) the official languages.

This article covers the history of the region from prehistoric time to the end of the colonial period in the 20th century. For the postcolonial history of the region, see Burundi, Central African Republic, Congo (Brazzaville), Congo (Kinshasa), Gabon, Rwanda, and São Tomé and Príncipe. Area, 1,402,367 square miles (3,632,116 square km). Pop (2001 est.) 75,001,000.