The Application of Geospatial Techniques in Flood Risk and Vulnerability Mapping for Disaster Management at Lokoja, Kogi State, Nigeria

Abstract

A flood risk and vulnerability assessment of Lokoja town in Nigeria was investigated. The objective is to identify the risk lives and vulnerability level of the settlement to flood disasters.  Geospatial techniques using remote sensing data and GIS was utilised in the analysis. Results indicate that the substantial part of the settlement falls within the high flood risk zone. The mapping identified three zones with respect to vulnerability level.  Buildings within 30 meters buffer distance from the river banks and flood plains are classified as highly vulnerable, 50 meters buffer distance is moderately vulnerable and 70 meters above as safe zones. Building challenges, rainfall impact and water releases from hydropower dam were identified as major causes of floods in the study area. It is recommended that continuous inventorying of hydroclimatic variables at dam reservoirs be intensified and adherence to site selection for building should continuously be enforced to reduce the risk levels and safeguard the settlement from flood disasters.

Keywords: Flood Mapping, Vulnerability, Risk, Rainfall, Drainage Basin, Buffer Distance