Geographic information system (GIS)-Based multicriteria analysis of flooding hazard and risk in Ambo Town and its watershed, West shoa zone, oromia regional State, Ethiopia

Abstract

The purpose of the study was to analyze flooding hazard and risk from Geographic Information Systems (GIS)-based multicriteria perspective in Ambo town and its watershed and proposes strategic measures for sustainable flooding disaster risk management in urban watershed. Land use/land cover, elevation, slope, drainage density, soil, and rainfall were considered as important flooding hazard factors. Analysis of flooding risk was undertaken for Ambo town’s watershed using flooding hazard layer and the two elements at risk, namely human population and land use. Weighted linear combination (WLC) method was used in the process of criteria map aggregation for both flooding hazard and flooding risk. The result of the flooding hazard in the watershed reveals that more proportion of the watershed is high and very high flooding hazard area (60.58%). Moreover, more proportion of the town is high and very high flooding hazard area (66.87%). The result of the flooding risk in the watershed reveals that more proportion of the watershed is high and very high flooding risk area (41.76%). Moreover, half of the town is high and very high flooding risk area (50.09%). An integrated basin wide approach to flood management should be practiced as it is essential to address multiple water related issues at watershed level. Moreover, environmental education should be emphasized to build civic responsibility among the citizens. Keywords: Flooding, Hazard, Land use management, Risk, Spatial planning