A comprehensive analysis of reservoir capacity loss: A case study of the Akhangaran reservoir, Uzbekistan

The purpose of this article is to analyze the loss of capacity in the Akhangaron reservoir due to sedimentation processes. With the reservoir having been in operation for 50 years, understanding the dynamics of its water reserves is crucial, especially considering the impact of siltation on its volume and functionality. Through detailed analysis, including bathymetric surveys and geostatistical methods, this study aims to assess the current state of the reservoir volume, identify trends in volume loss over time, and predict future capacity reductions. By providing valuable insights into sediment dynamics and reservoir capacity loss, the findings of this study seek to inform and guide future management strategies for the Akhangaron reservoir and similar water management systems. The obtained results showed that the analysis of the Akhangaron reservoir from 1972 to 2022 reveals significant volume losses, with a total reduction of 28.6 Mm 3 (14.44%), impacting both useful and dead volumes, demonstrated by a decrease in useful volume by 21.3 Mm 3 (11.52%) and a significant decrease in dead volume by 7.3 Mm 3 (55.73%). Additionally, surface area reductions at both full storage level (FSL) and dead storage level (DSL) underscore sedimentation's impact, particularly evident at lower water levels. The projections indicate significant declines in both total and useful volumes, essential for water supply and operational efficiency. By 2072, the total volume is expected to decrease by 39.45 %, while the useful volume is anticipated to drop by 36.45% over the same period. Of particular concern is the predicted reduction in the dead volume, crucial for sediment storage. By 2044, projections suggest that 82.28% of the dead volume will be lost, and by 2062, the dead volume is forecasted to be completely silted (100% loss), rendering the reservoir's regulating capacity unmanageable. • Evaluates sedimentation impacts on Akhangaran Reservoir's storage capacity over time. • Uses geostatistical analysis of bathymetric data to model sediment accumulation. • Operational volume decreased by 11.52 % and total volume by 14.44 % from 1972 to 2022. • Predictions a 39.45 % reduction in storage volume by 2072 due to sedimentation. • Recommends sediment management strategies to sustain reservoir functionality.