Integrating Remote Sensing and GIS Techniques for Flood Hazard Zoning and Risk Assessment in Rapidly Urbanizing Watershed in Edo State

Floods are natural phenomena that cannot be entirely prevented. It is a temporary covering by water of land normally not covered by water. This research evaluates the flood risk potential in the Agenebode Community in Edo State, Nigeria. The networks of rivers surrounding the entire watersheds were modeled in ArcGIS – ArcInfo 10 software using the digital elevation model data of the terrain. In the flood discharge analysis, Gumbel, Log Normal, and Log Pearson Type III distributions were used. Flood discharge for return periods of 2, 5, 10, 25, 50, 100, and 200 years was identified to inundate a surface area of approximately 0 m2, 652.9m2, 458.2m2, 51204.5m2, 105655.2m2, 206479.7m2, and 313928.1m2, respectively, in Agenebode. The magnitudes of flood discharges for return periods of 2 years, 5 years, 10 years, 25 years, 50 years, 100 years, and 200 years are 16,990.26m3/s, 21,159.94m3/s, 23,731.35m3/s, 26,817.19m3/s, 29,021.03m3/s, 31,153.24m3/s, and 33,250.88m3/s, respectively. The output showed that the topography of the community varies from 26m in the south-eastern part to 244m in the northwestern part. Highlands are mainly in the northwestern part of Agenebode; thus, water drains from west to east towards the River Niger.