Application of artificial countermeasures to enhance desilting efficiency in a reservoir under normal and extreme events

Abstract

The influx of flood-induced turbidity flows with high sediment concentrations into the reservoir can create sediment deposition issues, potentially jeopardizing water supply reliability. Efficient management of reservoir water resources is imperative for sustainable utilization. Evaluating the need for reservoir desilting involves comprehending the inflow and outflow dynamics of water-sediment discharges, the capacity of existing outlet structures, reservoir operation objectives, and available desilting technologies. However, given the altering hydrological conditions due to the impacts of climate change, there is a necessity for adaptive methods to ensure reservoir storage maintenance. Consequently, this study introduces the utilization of a flushing channel with artificial guiding structures to enhance desilting efficiency. A 2D numerical model offers convenient computational tools for assessing water-sediment transport behaviors across various operational scenarios based on reservoir management strategies. Data obtained from field observations is collected and analyzed to calibrate and verify the numerical model. By employing 2D numerical modeling, sediment concentration and desilting efficiency are calculated to support effective desilting operations within a reservoir. Simulation results indicate that the integration of additional artificial guiding structures at the bottom of the reservoir can enhance sedimentation mitigation outcomes by approximately 17.63% under normal conditions and by 5.27% under extreme hydrological conditions. HIGHLIGHTS A typical method is to prevent sediment movement toward the dam. We propose a new concept to partially guide and concentrate inflow sediment using artificial structures toward the outlet. This concept has not been proposed or discussed before.; We present the contribution of adapted artificial countermeasures under different hydrological conditions that can provide a reference strategy for worldwide reservoir management.;

Keywords

• adaptive methods
• artificial guiding structures
• desilting efficiency
• sediment deposition