Application of gis and analytical hierarchy process for flood vulnerability assessment in Adamawa Catchment, Nigeria

Abstract

This study applies Geographic Information System (GIS) and Analytical Hierarchy Process (AHP) to assess flood vulnerability in the Adamawa Catchment of Nigeria. Seven criteria (drainage, rainfall distribution, geology, land cover, elevation, slope, and soil) were analysed, and a pairwise comparison matrix was constructed. The analysis resulted in a flood vulnerability map depicting different levels of vulnerability. The reliability of the approach and results were validated with a Consistency Ratio of 0.0944 and found to be within the acceptable value for reasonable consistency. The methodology used therefore disclosed the areas vulnerable to flooding in the Adamawa catchment. The analysis revealed the following levels of vulnerability - low vulnerability (19.9%), moderate vulnerability (31.4%), high vulnerability (31.8%), and very high vulnerability (16.9%) respectively. The main river and tributaries are pinpointed as areas highly vulnerable to floods and therefore, might be significant contributors to flooding events in the catchment.