ASSESSMENT OF THE FLOOD REGIMES AND IMPACTS

ABSTRACT

This thesis assesses the flood regimes and impacts in Agenebode and Illushi in Nigeria in regard to frequency and impact of floods in the last decade. The aim of the study is to assess the flood regimes in Agenebode and Illushi Communities in Edo state, Nigeria. The Middle belt part of Nigeria is affected more by flooding than the south, so should be prioritized for flood forecast mapping and management. Both primary and secondary data were employed with focus climatic condition, land use and terrain of the study area, in order to capture the variability of the flood events on those environments.  The use of remote sensing data with GIS techniques is the most common approach to flood modelling, forecasting and management in Nigeria. Applying GIS-based multi-criteria analysis (MCA) to assess flood hazard is been used as an approach, in preference to process-based models. The research shows that flood events in these areas have seriously affected by the above listed factors especially climate change and land use, DEM generated from SRTM data for the area was used in this research to delineating drainage basins. Stream network of the area was digitized was from the topographic map of the study area. The resultant images for 2007 and 2021 showed a great reduction in vegetation and change in land cover by 62.29%. The change posed a risk of exposing the town to flooding. From the rainfall distribution data, the volume of runoff had increased over the years under study as the urbanization increase as shown by the different map produced in the work leading to the production of a flood risk map for adequate plan and prevention of loss of lives and livelihood.