Estimation of Sediments and Volumetric Analyses of Shiroro Dam Using Geospatial Technique

Abstract

To effectively manage reservoirs, there is need to routinely check the rate of sediment accumulation as it effects the capacity of the reservoir. Remote sensing technique provides useful alternative for extracting depth information and a fast, repetitive and low-cost mapping over large areas which optimize and minimize intensive field works. This study seeks to estimate the sediment accumulation of Shiroro reservoir in Niger state, Nigeria using Satellite-Derived Bathymetric (SDB) models (python script algorithm). Landsat8 image data (30 m resolution) was used for the research, the preprocessing and post processing stage was carried out aimed at increasing the reflectance of the image data. The sequence involves the derivation of depth using band ratio technique and the volume of the suspended sediment was estimated using python script on ArcGIS software. The estimated volume obtained was about 5365.47 Mm3 as against the reservoir designed volume of 7000 Mm³, it indicates a loss of about 1635 Mm3. The rate of sediment accumulation was estimated to be 70.02 Mm3/year which translate to be about 0.65% per year. The study recommend that further investigation should be carried out using different means of data acquisition to ascertain the outcome of the results obtained. However, routine checkup should be carried out to preserve the lifespan of the reservoir.