The Osse-Ossiomo River basin of Edo State, Nigeria, was investigated in terms of land-use changes from 1970 to 2000 using Geographic Information System (GIS) technology. The topographic map of 1965 and Landsat ETM images of 1987 and 2000 were used to investigate these changes. AutoCAD 2000, Arcview GIS 3.2 and Erdas Imagine 7.1 software were used. The results showed that land use in the Osse-Ossiomo River basin changed between 1970 and 2000. The built-up area is principally Benin City. As of 1965, the areal extent was about 25 km2 or 2500 ha, which increased to 645 km2 or 64,500 ha in 1987, and 804 km2 or 80,400 ha by 2000. The other settlements, which included many villages of different sizes (ranging from 5 to 10 km), have merged with the Benin City metropolitan area. The number of roads has increased and the original tropical rainforest vegetation is now a more open type of guinea savanna vegetation. The many rubber plantations that existed in the 1970s have been converted to built-up areas and farmlands. These changes are accompanied by the rapid rate of population growth in the metropolitan area. Appropriate land-use laws are recommended to check the eventual destruction of the natural ecosystem and the dynamic modification of the basin hydrology.
GIS, Land use, Osse-Ossiomo river basin
