Monitoring Reservoir Sedimentation at Shiroro Dam, Niger State Using Remote Sensing Techniques

Reservoir sedimentation poses a long-term threat to the operational lifespan and energy generation capacity of Nigeria's major hydroelectric dams, with Shiroro Dam in Niger State representing a critical national infrastructure asset. This study monitors reservoir sedimentation at Shiroro Dam using multi-temporal remote sensing techniques applied to Landsat 8 and Sentinel-2 imagery spanning the period 2018 to 2024. Water clarity and turbidity proxies are derived from near-infrared and red band ratios, and the spatial distribution of sediment-laden inflows is mapped during peak runoff periods in September and October of each study year. Normalised Difference Water Index analysis delineates the dynamic waterline position, enabling estimation of changes in reservoir surface area and the progradation of delta deposits at primary tributary inflows, particularly the Kaduna and Dinya rivers. Comparisons of the derived sedimentation indicators with archival bathymetric survey data from the Shiroro Hydro Electric Power Limited are used to validate remotely sensed sediment estimates. Results suggest continued active delta-building at the Kaduna River inlet, consistent with prior studies indicating accelerated upstream erosion. The findings support the case for urgent upstream watershed restoration and engineering assessments of viable sediment management interventions at Shiroro. Keywords: reservoir sedimentation, Shiroro Dam, remote sensing, Landsat, Niger State.