Physical Geography

Except for mountains rising to 7,963 feet (2,419 m) along the Cameroon border, Nigeria is a land of plains, hills, and plateaus. Fringing the coast is a narrow lowland of sandy beaches, mangrove swamps, lagoons, and interconnected rivers. Here, too, is the large Niger River delta. North of the coast lies a region, 50 to 100 miles (80 to 160 km) wide, of plateaus and rolling hills.

A broad upland, generally flat to rolling, spans central and northern Nigeria. It averages about 2,000 feet (610 m) in elevation; its highest part, on the Jos Plateau near Jos, rises to 5,843 feet (1,781 m) above sea level.

The principal rivers are the Niger and its main tributary, the Benue. Both are navigable over most of their courses within the country and together drain the greater part of Nigeria. Both offer hydroelectric power potential, some of which has been developed at the large Kainji Dam on the Niger. In the south, rivers tend to be short and carry relatively large amounts of water. In the drier north, many rivers carry water only part of the year. Nigeria shares Lake Chad with Niger, Chad, and Cameroon.

Nigeria lies about 4 to 14 north of the Equator and has a tropical climate that varies from south to north and with elevation. Southern Nigeria faces warm, moist, southwesterly winds from the sea during much of the year and is hot, humid, and oppressive. Temperatures average about 80 F. (27 C.) and have only a small daily and seasonal variation. Rainfall, which is heaviest during the summer months, is about 70 inches (1,780 mm) annually along the western part of the coast and up to 150 inches (3,810 mm) in the east.

Northern Nigeria is dominated most of the year by dry, dusty, northeast trade winds, called harmattans, from the Sahara The climate is drier than that of the south and is marked by a greater range of temperature. The hottest month averages about 90 F. (32 C.); the coolest, 70 F. (21 C.). Summer days are extremely hot, often reaching 100 to 110 F. (38 to 43 C.). Most of central Nigeria receives 25 to 50 inches (635 to 1,270 mm) of rain each year, nearly all of it during the summer. Winger is virtually rainless.

The natural vegetation of Nigeria varies with the climatic conditions, particularly the amount of precipitation Mangrove and swamp forests predominate in the delta and coastal zone; tropical rain forests, in the humid south; and savannas, in the subhumid central zone and the drier north. About one-eighth of Nigeria is covered with forests. Commercial use of the forests, however, is limited by inaccessibility, lack of solid stands, and poor timber quality in the drier areas.