Introduction

Nigeria is a country of remarkable diversity in its economy, physical conditions, vegetation and ethnic groups. The four main physical regions consist of the sparsely populated dense belt of swamp and mangrove forest along the coast; the tropical rainforest area; the open woodland and grass savanna; and the southern Saharan region (F.M.E.D., 1975). The differences in physical conditions and soil fertility in the regions have, in combination, helped to produce complementary economies: cocoa, palm produce, and rubber in the rain forest fertile areas; groundnut and cotton in the sandy soils of the savanna north; and rich oil deposits in the east (U.N.F.P.A., 1980). These remarkable regional variations strongly influence both the pattern of development and population distribution (Adepoju, 1982).

The salient demographic features include the young population (48 per cent are under age 15), which results from the high rate of population growth; low literacy; and a low level of urbanization. In 1980, only about one-quarter of the population lived in urban areas of 20,000 or more inhabitants. However, major cities are growing rapidly, with annual growth rates of between 5 and 10 per cent, sustained by both high rates of natural increase (2.9 per cent per annum) and rapidly accelerating in-migration from villages and smaller towns.

The economic development strategy inadvertently shaped the pattern of population distribution. Beginning from the later part of the colonial rule, changes – administrative and political – were introduced which also had the indirect effect of diversifying migratory flows in the country.