ANALYSIS OF TOPOGRAPHICAL CONTRIBUTION OF FLOODING IN OWERRI URBAN IMO STATE USING GIS AND REMOTE SENSING TECHNIQUES

Abstract

Flooding poses a significant environmental challenge in Owerri Urban, ImoState, Nigeria, exacerbated by rapid urbanization, inadequate infrastructure, and heavy rainfall.This study examines the topographical contributions to flooding in Owerri using GeographicInformation Systems (GIS) and remote sensing techniques. By analysing Digital ElevationModels (DEM), slope gradients, hill shade, aspect, and contour maps, the study identifies keyareas prone to flooding. The findings reveal that flat or gently sloping areas, particularly thosewith a slope gradient of 0° to 40°, are most susceptible to run-off accumulation and floodevents. The study further highlights the role of flat or gently sloping areas (0° to 40° slopegradient) in contributing to flood risk.", especially at the bases of slopes, where runoff fromhigher elevations accumulates. These insights underscore the critical role of topography inflood risk assessment and provide a foundation for developing targeted flood mitigationstrategies. The study recommends the construction of a comprehensive drainage network, theintegration of flood risk maps into urban planning, and the enforcement of land use regulationsto reduce flooding in Owerri Urban. The use of GIS and remote sensing in this analysisdemonstrates their effectiveness in enhancing urban resilience to environmental hazards.