Authors: Kayode Julius Samuel; Remilekun Eunice Atobatele
Addresses: Human Settlements Research Unit, Mangosuthu University of Technology, 511 Mangosuthu Highway, Umlazi, Durban, KwaZulu-Natal, 4031, South Africa ' Department of Geography, Osun State University, P.M.B. 4494, Osogbo, Osun State, Nigeria
Abstract: This study examined the trend in urban growth and vegetation loss and the implication of this on the sustainability of medium-sized cities, using Osogbo, south-west Nigeria as a case. Using multi-temporal Landsat™ images that span 30 years (1986 to 2016), the study employed supervised classification to categorise the land cover into the built-up area, vegetation and water bodies. Findings revealed that the city grew axially along major transportation corridors in the early stage but experienced in-filling, densification and radial outward growth subsequently. The built-up area increased at annual rate of 14.7%, more than the population growth rate of 2.2% while vegetation cover and water bodies recorded an annual change of −2.5% and −3.5% respectively. Rapid city growth and the resultant land use/cover conversion contribute to the depletion of wetlands and vegetation, thereby constituting a threat to sustainable urban development. Controlled urbanisation is suggested as a panacea to the unsustainable urban expansion which threatens the city's ecological equilibrium.
Keywords: urbanisation; medium-sized city; sustainable growth; vegetation; land use; land cover change; supervised classification; ecological equilibrium; urban expansion; wetlands; sustainable urban development; controlled urbanisation.
International Journal of Sustainable Society, 2019 Vol.11 No.1, pp.13 - 28
Received: 08 Mar 2018
Accepted: 25 Oct 2018
Published online: 28 Aug 2019 *