Study of Short-term Longitudinal Profile and Sediment Dynamics of Ikpoba Reservoir

Abstract

<title>Abstract</title> Complex depositional systems, exemplified by dam reservoirs, pose significant challenges to natural sediment flow in river courses, impacting operational efficiency. This study focuses on the Ikpoba Dam, a critical water source for Benin City, facing functionality issues due to sedimentation. Through repeated bathymetric surveys conducted during wet and dry seasons, the research maps the dam's bed-floor topography. Analysis using empirical formulae and a geospatial approach unveils short-term sediment accumulation dynamics, emphasizing seasonal variations. Results indicate a sediment volume of 400,000 cubic meters in the 2019 survey, translating to 73.33% loss in storage capacity over 44 years, at an estimated rate of 1.66 m^3/year. Verification of bed profile results demonstrates high reliability, with root mean square errors ranging from 90–93%, employing ArcGIS 10.4. Notably, the study identifies a substantial sediment accumulation of 840,127.34 cubic meters. These findings are pivotal for formulating dredging plans essential for dam revamping initiatives, aiming to optimize efficiency while mitigating sedimentation challenges.