Exponent determination in a poorly gauged basin system in Nigeria based on flow characteristics investigation and regionalization method

Abstract In this study, a method for estimating the exponent “ n ” values of catchment-area equations four sub-basins within poorly gauged Benin-Owena River Basin Development Authority (BORBDA) in Nigeria is presented to enable estimation flows at ungauged sites basin and determination small hydropower (SHP) potential different locations each sub-basin entire basin. Optimal prediction streamflow characteristics requires developing methodology extrapolation data from Four sub-catchments BORBDA, Nigeria, were investigated using Remote Sensing (RS), Geographic Information System (GIS), statistical techniques, Natural Resources Conservation Service-Curve Number (NRCS-CN) hydrological model. Discharge (Q g ) obtained recorded discharge collected 12 months an established gauging station sub-basin. RS GIS techniques used develop classification maps obtain crucial like curve number (CN), elevation, Hydrologic Soil Group (HSG), rainfall intensity, slope, area required evaluating spatial (ungauged) utilizing NRCS-CN From model sub-basin, relationship between catchment was be 0.23, 0.41, 0.71, 0.74. Using lumped modeling approach, which considers watershed as single unit computation, where parameters variables averaged produced = 0.52 BORBDA area, range 0.5–0.85 suggested by previous researchers. Obtained validated use through soil homogeneity test generating map confirms share similar HSG A, B, D with BORBDA. The value useful predicting parts helpful assessment SHP basin, dissemination research findings will find practical guide practicing hydrologists around world challenges basins particularly Africa other countries.