Cameroon - Geography

A country with an area of approximately 183,500 square miles, Cameroon is often referred to as the hinge between West and Central Africa, as it incorporates many of the physical and human features of both. It is roughly triangular in shape, having a wide basin in the south, where it borders Equatorial Guinea, Gabon, and the People's Republic of the Congo (Congo — formerly, Congo Brazzaville). Cameroon forms an irregular wedge extending northeastward from a coastline on the Gulf of Guinea, an arm of the Atlantic Ocean, to Lake Chad, 700 miles inland. Its apex extends into Lake Chad some 700 miles to the north. Its western boundary is flanked by the Gulf of Guinea and by Nigeria. Eastern neighbors are Chad and the Central African Republic.

Cameroon is divided into four distinct topographical regions. Behind the swamps and the lowlands generally referred to as the southwestern coastal zone, the land rises to mountains and plateaus extending more than 500 miles inland before descending to a flat plain of moderate elevation in the far north. In the southwest a low coastal plain gives way inland to plateaus covered by equatorial rain forests. In the center of the country an ex- tensive savanna-covered plateau rises to heights of 4,500 feet above sea level. The west is an area of mountainous forests and the site of Mount Cameroon, an active volcano, whose height of 13,350 feet marks it as the loftiest peak in sub-Saharan West Africa. The northern part of the country consists of rolling subarid savanna, gradually sloping to a marshy flood plain along Lake Chad and the Chari and Logone rivers.

Natural vegetation in most of the south and in the southwestern coastal zone is a dense, tall evergreen rain forest. On the southern and southwestern plateaus, about 100 miles from the southern border and equidistant from the southwestern coast, the natural cover is a mixture of evergreen and deciduous forests. Deeper inland, at about 5°N latitude, the natural cover is wooded savanna—a mixture of grassland, scattered trees, and patches of forest, shading into open grassland with fewer trees in areas still farther north. Much of the northern plain produces only scrub and sparse grasses, but there are contrasting areas of swamp vegetation in the flood plains of the Chari and Logone rivers, which mark segments of the northeastern border.

The country has a 160-mile coastline on the Gulf of Guinea and approximately 2,765 miles of border with six countries: Nigeria to the west; Chad and the Central African Republic (CAR) to the northeast and the east; and the People's Republic of the Congo (Congo — formerly, Congo Brazzaville), Gabon, and Equatorial Guinea to the south. Many of the borders in 1973 were originally marked out during a century of competition for territory among the colonial powers of Germany, France, and Great Britain.

The Cameroon-Nigeria boundary extends generally northeastward from the coastline for 1,050 miles to a tripoint in Lake Chad, deep in north-central Africa. Various segments were originally established through agreements between former colonial powers or by unilateral decisions of the British government, which controlled areas on both sides of this border until after World War II.

Near the coast some sections are marked by broken terrain and heavy forests, but there are also numerous areas where foot travelers can easily cross. Farther inland, movement is generally not difficult in the savanna grasslands and open forests that mark the central reaches of the border, even though some segments are marked by mountains of moderate elevation.

Four loosely defined regions provide a useful descriptive framework: the northern plains, the central and southern plateaus, the western highlands and mountains, and the lowlands along the coast.

Northern Plains

The northernmost area of the country extends into Lake Chad, where the borders of Nigeria, Chad, and Cameroon intersect. The narrow neck of territory south of the lake is part of a shallow inland basin, several hundred miles wide, which extends in all directions from Lake Chad. Broad areas of low, rolling hills bear little vegetation on their thin soils; other areas are flat, marked here and there by scattered outcrops or hills of resistant rock rising above the general erosional level. West of Maroua the scattered rocky mounds and minor ridges are more numerous, rising westward to hills and elongated ridges. Central and Southern Plateaus

The Adamaoua Plateau, lying between 7°N and 9°N latitude, extends from the eastern to the western border of Cameroon at elevations that are everywhere more than 3,000 feet above sea level and average about 4,500 feet. Surface features in the central parts of this high plateau include small hills or mounds capped by erosion-resistant granite or gneiss. Along the western and, to a lesser degree, the eastern borders, old eruptions from fissures and volcanoes have covered thousands of square miles of the underlying granite with lava.

South of the Adamaoua Plateau begins a series of lower plateaus that extend throughout most of South Central and Eastern provinces at elevations averaging about 3,000 feet but descending gradually southward to the border and westward toward a series of terraces leading downward to the coastal plain. The surfaces of these extensive southern plateaus are primarily mixtures of ancient granite and sedimentary rock. Soils are shallow in most areas and, for the most part, have been formed from the underlying granite.

Western Highlands

The Cameroon Mountains, the highest range in the country, extend southeastward from the Cameroon-Nigeria border area at about 7°N latitude to Mount Cameroon on the coast. The major mountain range and the upland areas on its eastern and western slopes were built up by volcanic activity associated with a series of faults in the granite substructures underlying the African continent.

All of the ancient volcanoes in this complex had subsided before the dawn of recorded history except for Mount Cameroon, which has been active on four occasions during this century: 1909,1922,1954, and 1959. In 1922 and 1959 molten lava flowed several miles, destroying plantations on the lower slopes. The mountain is a complex of several connected fissures and cones, one of which reaches 13,350 feet above sea level, more than half again as high as any other peak in the country. Elsewhere in the Cameroon Mountains, elevations range between 5,500 and 8,000 feet.

Other ranges of lower elevation stand in the north near the western border of Northern Province. The most important of these are the Alantika Mountains, which mark the border for a short distance at about 8°30'N latitude, and the Mandara Hills, which extend northward from the town of Garoua and the Benoue River to about 11 °N latitude.

Coastal Zone

Most of the coastal zone is a flat area of sedimentary soils that front on the Gulf of Guinea for about 160 miles. It is less than twenty miles wide in most of the area northwest of Mount Cameroon, which divides the northwestern coastal plain from the broader lowlands in the central coastal area. Around Douala, the lowlands extend inland as much as fifty miles, narrowing to as little as five miles farther south. Along its seaward edges the central segment of the coastal zone is a series of many adjoining deltas.

Numerous rivers, fed by heavy rains during most of the year in the coastal zone and the adjacent plateaus and mountains, continue to expand the deltas with erosional debris. Near their mouths the major rivers, which are partially choked by this debris, divide into numerous sluggish channels. The various estuaries are tangled complexes of these channels and are also fed by small local streams.

Close to the coast the older deltas and flat swamplands are covered with mangrove trees and other swampland vegetation. From these coastal flats the plains rise very gradually to about 300 feet above sea level. At approximately this level, a relatively abrupt increase in slope marks the first of several steps, or benches, leading upward to the inland plateaus.

Drainage Patterns

Most surface runoff from Cameroon eventually flows westward to the Atlantic Ocean—much of it by circuitous routes and by way of external river systems, such as the Niger and the Congo. Three primary watershed ridgelines divide the country: the centrally located Adamaoua Plateau, a poorly defined north-south ridgeline in Eastern Province, and the Cameroon Mountains.

Rivers in Northern Province, where annual wet and dry seasons occur, exhibit major seasonal fluctuations in volume. Practically all rivers in the other six provinces carry a heavy flow for most of the year; most areas south of 5°N latitude have two rainfall and runoff maxi- mums per year, but the variations in flow are within much narrower limits than those observed on northern streams.

The extreme north is a complex, relatively flat area of inland basins that have no outlet to the sea. The Logone and Chari river systems along the northeastern border annually inundate a broad area before emptying into Lake Chad, the major inland basin in this part of the continent. Most of these floodwaters are not collected locally but have been brought from high rainfall areas farther south in eastern Cameroon, in CAR, and in Chad. Most other rivers in the north flow only during the rainy half of the year and disappear in the sands and swamps of other shallow inland basins.

Some of the runoff originating on the Adamaoua Plateau flows northward into the upper tributaries of the Benoue River, which winds across the western border and joins the Niger, the major river in Nigeria. By way of several tributaries, the Niger also receives a heavy flow from the Cameroon Mountains and from associated highlands in Northwestern and Southwestern provinces.

Various streams originating in the southern part of the Adamaoua Plateau feed into the Sanaga, the largest river in the southwestern part of the country. This river also collects a huge flow from heavy rainfall areas on the eastern slopes of the Cameroon Mountains and channels this heavy runoff into the Atlantic Ocean south of Douala. Three other major rivers—the Wouri, Dibamba, and Nyong—also feed into the tangled complex of deltas on the central Atlantic coast. Farther south, near the borders with Equatorial Guinea and Gabon, the Campo River watershed extends inland for about 200 miles.

Both the Sanaga and the Nyong rivers collect runoff from parts of Eastern Province, but most of this very wet forest area is drained by various tributaries of the Sangha River, which for a short distance marks the border with the Congo and then flows southward into the Congo River.