Available data on urbanisation in Nigeria is largely conflicting. UN-Habitat and the World Bank are the most frequently cited sources of urban population statistics. However, their data are sometimes misleading and appear exaggerated.
In Nigeria, virtually every census since 1952 has been highly contested. This is perhaps due to both political and economic reasons. Economically, federal statutory allocation to states is influenced by their population. Thus states with reportedly low populations are disadvantaged in resource allocation from the federal level.
Politically, in the democratic setting politics is a game of numbers and political parties controlling large population can be at an advantage. Population is also one of the indices upon which parliamentary representation is based. Despite the controversies, available data give sufficient indications of Nigeria‟s urban status
Long before the British colonial administration in Nigeria, there were already in existence fairly large human settlements . These were mainly driven by trade (including slave trade) and administration. However, pre-independence Nigeria had a very low urban population as well as urban population growth.
As at 1921, only ten Nigerian settlements had urban status and by 1931 only two cities, Lagos and Ibadan had populations in excess of a hundred thousand people each. Post-independence Nigeria witnessed more rapid rate of urbanization.
Nigeria since independence has become an increasingly urbanised and urban-oriented society. By the early 1960s the cities of Lagos and Ibadan had populations in excess of half a million people each.
In addition, there were twenty four cities with populations of not less than a hundred thousand people. However, it was not until the period between 1970 and 1995 that Nigeria witnessed an unprecedented high level of urbanisation reputedly the fastest urbanisation growth rate in the world at the time. By 1991, Nigeria was reportedly 37% urbanised.
The rapid growth rate of urban population in Nigeria was spurred by the oil boom prosperity of the 1970s and resultant massive development projects in the country which catalysed a great influx of people into urban areas.
The factors responsible for the high urbanisation in Nigeria was as follows:
The oil boom of the 1970s and early 1980s;
Government policies which resulted in the creation of new states and local government areas;
Creation of a new federal capital territory in Abuja;
Establishment of new universities; and
Large scale government sponsored construction projects including sea ports, refineries and steel companies.
In 1990 there were twenty-one state capitals in Nigeria, with estimated populations of at least 100,000 inhabitants each which were projected to double every fifteen years (U.S. Library of Congress, 2013). According to statistics 43.5% of the Nigeria people lived in urban areas as at 2000. Now we have approximately 50% of our population living in urban cities with predictions that the urban population will hit the 65% mark by the year 2020.
Like what obtains in other developing countries, rapid urban growth in Nigeria has outpaced capacity of government to plan for it. Often, growth occurs so quickly that government officials do not have relevant statistics needed for sustainable development.
Another constraint has been dwindling national resources which have further been depleted by massive and uncontrolled corruption. Consequently development is meager, insufficient and not associated with the commensurate economic growth and effective redistributive measures required to alleviate poverty and create economic opportunities needed to improve living standards and quality of life of the people.
A crucial aspect of this is that city growth and expansion in Nigeria has been largely uncontrolled thus compounding problems in Nigerian. These problems include inadequate and poor housing; slum areas; inadequate water supply; waste disposal; traffic and human congestion; high rates of unemployment and underdevelopment; poverty; crime and other social problems.
Although studies have shown that the problem of housing is universal, it is more critical in developing countries like Nigeria because of its magnitude and lack of resources to tackle it. About 60-70% of Nigerian urban dwellers live in slums. Nigeria is highly vulnerable to the impact of climate change. Virtually every Nigerian city is vulnerable to natural or man-made disasters. The poor however have greater difficulties recovering from disasters.
In August 1988 for instance, 142 people died, 18,000 houses were destroyed and 14,000 farms were swept away when the Bagauda Dam collapsed following a flash flood. Urban flooding occur in towns located on flat or low lying terrain especially where little or no provision has been made for surface drainage, or where existing drainage has been blocked with waste, refuse and eroded soil sediments.
Extensive flooding is a phenomenon of every rainy session in Lagos and other cities and does pose a threat to prime property areas. In late 2012, many parts of Nigeria experienced an unprecedented mass flooding which reportedly destroyed several lives and properties including farm lands and livestock.
Nigeria‟s socio-economic and environmental indicators show very poor performance across the board. Poverty is an acute problem in Nigeria. Nigeria has one of the highest poverty rates in sub-Saharan Africa with 70% of her population below poverty line, which is the sixth highest in the world. The country also has probably the third largest number of poor in the world, after China and India.
Although at 3%, extreme poverty was virtually non-existent in Nigeria‟s urban areas in 1980, by 1996 about one quarter of the urban population was poor. Urban poverty levels increased from 28% in 1980 to 66% in 1996. In 2000 the maternal mortality rate in Nigeria was estimated at 800 deaths per 100,000 live births. Life expectancy is the most common indicator of health conditions in a country.
In addition, May 2016 life expectancy data published by the World Health Organisation (WHO) has shown that Nigeria, again, has one of the lowest life expectancy ratio in Africa and in the world; with 55 years for females and 54 years for males, standing at the 177th position, just above eight other countries of the world.
Lagos remains the most urbanised city in Nigeria with a population of over 21 million people. The city is also the fastest growing city in Africa.