GIS and RS Techniques for Identification of Hydropower Potential Sites in Benin-Owena River Basin in Nigeria

Abstract

Nigeria’s overall energy access is 60% with 86% urban and 34% rural rates, and over 20 million households without power in 2018; there is need for continuous investment in Nigeria’s energy sector due to the epileptic supply nature. Sustainable way to alleviate poverty in rural communities is to establish clean and affordable energy initiatives. Reports indicated that hydropower is a feasible alternative in Nigeria’s South-South geo-political region, with huge potential for Small Hydropower (SHP) development. In this study, the SHP potentials of Okhunwan river in the Benin-Owena drainage basin, Nigeria is investigated. The discharge was computed by the NRCS-CN model using 2018 monthly PERSIANN-CDR, slope, CN data, etc. as inputs and statistically compared with observed data collected from gauging station; indicating 0.75 as average correlation between simulated and observed. Validation between NIMET data from Benin City Synoptic station and PERSIANN datasets for Okhunwan sub-basin indicated average spatial correlation coefficients of 0.75. This study utilized GIS spatial data analysis and RS to obtain classification maps (CN, slope, soil, LULC, rainfall and DEM), where necessary data were extracted to evaluate SHP sites. Thirty-seven hydrometric points were mapped along the tributaries and main river courses of Okhunwan at 2km set points and considering the optimization criteria that a viable SHP site must have 2% minimum slope and 10m available head, 5 points were identified; with power ranging between 149.583 – 16,935.279 kW at 92% flow exceedance annually. Providing electricity from the identified SHP sites will enhance human development index of Benin-Owena river basin residents.