FLOOD VULNERABILITY ASSESSMENT IN OVIA-NORTH EAST

ABSTRACT

Flooding brought on by excessive rainfall is one of the frequently occurring and widely reported disasters. The purpose of this study is to offer expertise in creating flood risk maps that can be used by the public and in estimating the likelihood of flooding in rapidly expanding urban areas. An integrated Analytical Hierarchy Process (AHP) and Geographic Information System (GIS) analytic technique is used for the example of Benin City in Nigeria to model and estimate the extent of flood risk zones. A spatial decision support system was made to analyze the flood risk in Benin Metropolis. Among the fundamental datasets requirements for the project were: cloud-free high-resolution satellite images, SRTM DEM data, FAO soil data, rainfall data, etc. Maps of flood-enhancing elements, such as flood risk vulnerability mapping, were created in Geographic Information Systems using the same scale of 1: 400,000 and geographic coordinate system. This multi-parametric technique includes rainfall distribution, elevation and slope, drainage network and density, land use/land cover, and soil type, among other elements that cause floods (WGS 1984 zone 31N). All the output raster maps were first ranked using the "Weighted Linear Combination" method with a grid cell size of 0.0028 mm before being sent for Multi-Criteria Analysis (MCA). The computation of the consistency ratio at an acceptable level of 0.037 further confirmed the model's validity. Additionally, the research found topography and rainfall as significant factors contributing to floods in Benin City.