Geospatial-Based Multi-Criteria Decision Making for Flood Hazard Assessment in Ala-River Basin, Akure, Southwest Nigeria

Abstract

Periodic flooding endangers lives and properties of residents who settle in an unsafe location in Akure, Ondo State, such as the Ala River basin, that is prone to flooding. Essentially, this study presents a geospatial evaluation of flood hazard in Ala River Basin, Akure LGAs, Ondo State, Nigeria, using a GIS-based approach to integrate primary and existing data. The research examines land use/land cover dynamics, identify flood-predisposed portions, and generates a vulnerability map of Ala River. This was achieved through extensible fieldwork, GIS operations (vectorization and reclassification), and Multi-Criteria Decision Making (MCDM) deployed to pinpoint areas of high, medium, and low flood vulnerability methodically extracted from satellite imagery, SRTM DEM, soil data, and historical rainfall patterns of the study area. Findings revealed that slope, rainfall, and proximity to the river as key contributors to flooding, with the entire study area susceptible resulting to loss of properties and risk to life. This assessment provides a framework for flood hazard management, highlighting the need for targeted mitigation strategies to enhance resilience in Ala River Basin. Also, government must sensitize the people about the imminent danger in the high prone area identified on regularly basis particularly during the pick of rainfall.

DOI: https://doi.org/10.5281/zenodo.20376647