Geospatial Analysis of Flood Risk and Disaster Management in Kogi State

Abstract

Abstract A flood risk and vulnerability assessment of Kogi state, 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 were utilized in the analysis. Results indicate that, majority of the settlements are very vulnerable to flooding. It can be seen from the second flood risk map. After the overlay function has been made (overlaying of major settlements, stream network, digital elevation model, river and stream network buffer). It was observed that most of the settlements in Lokoja and environs are located on and around the stream network and on the flood plain. Any discharge or release of water in any form over this terrain, will lead to accumulation of water in the stream network expanding its course and increase in sea level rise, which may likely result to devastating flood events. A proximity analysis was carried out; a query was done to check the proximity of features to the stream networks. it is seen that built up or urban areas within the 1000m buffer zone are areas that are vulnerable to flood when there is extreme release of water in any form (heavy rainfall, release of water from dam or dam failure) but areas above 1000m buffer zone are areas that less vulnerable under the same condition. 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.