A spatial temporal analysis of wetland losses in the Lagos coastal region, Southwestern Nigeria, using multi-date satellite imagery

Abstract

This paper assesses the temporal trend and the spatial patterns of wetland forest loss in the Lagos coastal region of southwestern Nigeria between 1978 and 2006 based on the comparative analysis of multi-date satellite imageries for 1978, 1987, 1995, 2000 and 2006. The initial number of wetland habitats was derived using an unsupervised classification algorithm. Freshwater and mangrove swamp forests dominated the area. Generally, the wetlands declined by 19% between 1978 and 2006 at 0.6% annual rate of loss. The freshwater and mangrove swamp forests declined by 20.9% and 13.0% with an annual rate of loss of 0.7% and 0.43% respectively. Using the Markov Chain technique, the trend in wetland loss would likely continue if the current economic, social and political systems are maintained. The lower rate of decline of mangrove forests compared with freshwater swamp forests is a reflection of the more waterlogged and difficult terrain.