A model-based flood hazard mapping in Itang District of the Gambella region, Ethiopia

Abstract

Flood-vulnerable area identification as a measure of comprehensive flood risk management was investigated in Itang District, Ethiopia, using Probability Distribution and Analytical Hierarchy Process. The former provided a best fit to the extreme value analyses. According to water discharge levels, the region was mapped at 5, 10, 25, 50, and 100 year intervals. The parameters processed were slope, elevation, land-use/land-cover, rainfall, discharge, and soil. Each criterion was evaluated with Analytical Hierarchy Process and mapped by GIS. Data were assorted into very high, high, moderate, low, and very low suitability classes representing 29.7%, 27.8%, 18.5%, 12.7%, and 11.4% inundation areas, respectively. The outcome was found to be extremely useful for evacuation planning, damage assessment, and loss estimation to minimize the disaster effects in the district.

Keywords

• analytic hierarchy process
• frequency factor
• flood hazard zone
• gumbel distribution