Rapid urbanization and the growth of large cities in developing countries have been accompanied by the expansion of highly vulnerable urban communities living in informal settlements, many of which are on land exposed to extreme weather (IPCC 2014). Nigerian cities particularly Kano is among the cities in developing countries that experienced such expansion of communities living in an informal settlement and extreme weather, which the temperature reached 40 to 45 in °C between March and May.
Concept of Urbanization
Urbanization is a process of population concentration that proceeds through the multiplication of points of concentration and the increase in the size of individual concentration seems quite appropriate (Barry, 1973). Hope and Lekorwe, (2009) defined urbanization as the annual rate of change of the percentage of people living in urban areas, or the difference between the growth rate of urban population and that of the total population. It is the process of transformation that affects geographic regions when they become more urban, and that during the processes of urbanization, a growing share of a region’s land and people become included in cities (Pivo, 1996).
Urbanization causes a lot of environmental impacts, in Nigeria two dimensions of impact can be identified thus;
- Site impact
- The wider regional impact
These are negative effects of urbanization that are noticeable within each urban center. They are common to almost all towns and cities in Nigeria, they are;
Air and Noise Pollution
Air pollution; Most of the gases and particles that people are subjected to while breathing air, came from combustion (burning) processes. That is the furnace in factories, homes, and office buildings, the engine in automobiles, airplanes and other motor vehicles, and the burning of garbage and trashes are the major sources of pollution from combustion. Pollution from these sources has a wide variety of effects.
Noise pollution; Noise is the composite of many different sounds generated by human activities and it's getting worse by the day. Audiologists reported that urbanization is the major source of noise. Part of this pollution results from population growth as there are more people making noise. In addition, homes and workplaces must be built and food has to be raised for a growing population. People need transportation to travel between home and workplaces. In their leisure time, they enjoy sport most especially watching football in view centers. All these needs and activities are further sources of noise.
Solid waste problem
Solid waste is probably the most visible form of pollution. People throw-away billions of tons of solid material each year. Much of these wastes end up littering roadsides and collecting in ugly dumps. These problems are most common in populated areas in and near cities. One of the common methods of disposal of solid waste in Nigeria is dumping, in which people simply dumped their wastes on open ground.
Wider regional impact
Urban regional impact is a reflection of the enormous demand which urban center make on regional resources. These includes; Fuel wood demand, Road construction demand and Building materials demand. Fuel wood is brought into the urban center from the surrounding regions on a daily basis. It is extracted from the farms and dead trees in the forest. Increasingly, live trees are being cutting down daily and their stems are converting into fuel wood. This demand increase with the rise in level of urban poverty and with ever increasing of price of kerosene. Urban road network construction requires laterite, sand and gravels, which are obtained from quarries in the surrounding areas. The quarries are often abandoned later and become gullies or stagnant water ponds. Slumping, collapsed valley and roadsides are also associated with these quarries. Lastly, the bulk of materials needed for construction of building in cities like Kano are derived from the surrounding regions. These materials include sand, gravels, stones and wood. Excavation of sand, gravels, and stones create menacing quarries in the environment.
It could be concluded that the demand made by urban centers on the resources of their surrounding areas has led to indiscriminate exploitation of these resources and therefore, environmental degradation policies and measures must be spelled out and implemented to guide the behavior of urban dwellers and the exploitation of environmental resources.
Firstly, Programme of education and awareness aimed at bringing about attitude change with regards to environmental sanitation is highly recommended.
Secondly, a waste management board and not just an environmental sanitation agency is highly needed for our urban center.
Thirdly, land use regulations in the urban centers should be adhered to. When activities are carried out in their proper and district locations, the result is a clean healthy and beautiful environment devoid of conflicts.
Berry B. J. L. (1973), Human consequences of urbanization. The University of Chicago Press.
Hope K. R. and M. Lekorwe, (2009). Urbanization and the Environment in Southern Africa:
Towards a Managed Framework for the Sustainability of Cities. Journ. Environ. Plann.
Mgt. 42:6. 837–59.
IPCC, (2014), Climate Change 2014: Impacts, adaptation, and Vulnerability. Part A: Global and
Sectoral Aspects. Contribution of working group II to the fifth Assessment Report of the
Intergovernmental panel on climate change. Cambridge University Press, 1132pp.
Pivo, G. (1996). Towards Sustainable Urbanization on Main-street Cascadia Cities. Int. Journ. of
Urb. Policy and Plan. 13:5, 1314 – 1319.
Aliyu Mohammed Lawan is a Lecturer II in the Department of Geology in Skyline University Nigeria. He holds a Master’s degree in Applied Geophysics from Ahmadu Bello University, Zaria.