Morphological Implications of Urban Growth on The Insularity of Urbanized Islands; The Island of Lagos as Case Study

Abstract

Coastal areas and Islands are always the worst hit by the prevailing global urbanization and urban growth phenomena. Understanding the Spatio-temporal pattern of expansion of urbanized islands has become very pertinent to salvage the insularity and diversity of resources therein. The goal of this study is to evaluate the spatial change in the morphology of the island of Lagos over 165 years (1850 to 2015) period and its implication on island development. Descriptive analyses of demographic census data, documented and oral historical materials and remotely-sensed spatial data were undertaken. The results indicate that the rate of population growth is proportional to land expansion despite limited spatiality. There has been a steady increase in population over the century and a complementary expansion in space both laterally and vertically. While the land area increased from 13.64km² in 1962 (just after independence) by 49.85% to 20.44km² in 2015 through reclamation of adjourning wetlands, the population inhabiting the island shot up astronomically from 235,052 in 1962 to 1,423,961 in 2015 representing a 505% rise. The urban expansion pattern on the island between 1984 and 2015 revealed an increase in built-up area from 5.63km² to 12.95km² and a reduction in vegetal cover from 7.33km² to 0.83km² respectively, with associated impacts. This seeming unabated unsustainable growth and expansion portend grave environmental implications especially for island stability as well as climate change, thereby justifying the need for a holistic coastal zone and island management framework, to provide a guide for development on the urbanized island sustainably.