Flood investigation and adaptation strategies through best management practices in an ungauged basin in Southwest Nigeria

Morphometric analysis and hydrologic modeling was employed to investigate flooding, and test Best Management Practices (BMPs) in an ungauged basin. The Soil and Water Assessment Tool (SWAT) was employed to model the annual runoff/sub-basin for the year 2015, and to test BMPs –contour farming, terraces, and check dams for runoff reduction. The sub-basins were classified into low, medium, and high flood susceptibility. The rainfall-runoff hydrograph showed that runoff peaks closely follows rainfall peaks. Contour farming, terraces, and check dams presented a runoff decrease of 12.06%, 21.06% and 10.05%. The study provides good reliability in flood investigations and testing of BMPs.