This study evaluates the environmental vulnerability of Efon-Alaye located in Ekiti State, Nigeria, which is a typical mountainous region with steep slope and an upland ecosystem. An Integrated Remote Sensing and Geographical Information System approach was used to analyse the environmental vulnerability of the region. Satellite data of the study area for two periods 1986 and 2002 were used for the analysis. Spatial multi-criteria evaluation operation was used to generate the vulnerability map of the study area. Indicators used were land-use, vegetation map (NDVI) and slope map generated from digital elevation model. The vulnerability distribution was classified into five levels: potential, slight, moderate, high and extreme. The results show that the environmental vulnerability in the study is at potential level and the driving force of this change is attributed mainly to the cultural activities of the inhabitants of the study area. The result of this study has also shown that using Integrating remote sensing, geographical information system and spatial multi-criteria evaluation model to evaluate environmental vulnerability in mountainous regions will assist decision makers in environmental management.

Key words: Environmental vulnerability, spatial multi-criteria evaluation model, GIS, remote sensing, vegetation, land-use.