Land use and land cover change detection with remote sensing and GIS at metropolitan Lagos, Nigeria (1984-2002)

Lagos is the fastest growing mega-city in the world (UN, 2006), yet it lacks reliable, modern scientific monitoring techniques to effectively monitor and manage the unprecedented rapid land use/cover changes brought about by urbanization. The capabilities of satellite remote sensing in terms of large spatial coverage, spatial and temporal resolutions adequate for these types of studies, as well as the ability of GIS to handle spatial and non-spatial data, make in the optimal approach for this research. A post-classification approach was adopted with a maximum likelihood classifier algorithm. The Landsat Thematic Mapper (1984) and Landsat ETM (2000) were merged with SPOT-PAN (2002) to improve classification accuracies and provide more accurate maps for land use/cover change and analysis. This also made it possible to overcome the problem of spectral confusion between some urban land use classes. The land cover change map revealed that forest, low density residential and agricultural land uses are most threatened, and most land allocated for these uses has been legally or illegally converted to other land uses within and outside the metropolis. Also, the Lagos State land use map was 35% inaccurate. The research explored the underlining socio-economic and political factors which are driving the rapid land use/cover change in metropolitan Lagos, as well as the inter-relationship between population and spatial growth with the aim of using remote sensing and GIS to provide much needed intelligence to achieve sustainable urban and environmental development and planning in the study area.