EFFECTIVENESS OF ADVANCED RESERVOIR OPERATION TECHNIQUES FOR OPTIMIZING THE OPERATION OF SONG TRANH 2 RESERVOIR, CENTRAL VIETNAM

The Vu Gia–Thu Bon River Basin (VGTBRB) in central Vietnam frequently experiences severe flood events, posing significant challenges to downstream communities and water resource management. This study develops and applies an optimal reservoir operation model for the Song Tranh 2 (ST2) reservoir, a key upstream storage facility within the VGTBRB. The model integrates RTC-Tools (developed by Deltares, Netherlands) with advanced optimization methods, including the Shuffled Complex Evolution – University of Arizona (SCE-UA) algorithm for global parameter optimization and Model Predictive Control (MPC) for generating dynamic release strategies that balance multiple objectives over a forecast horizon. The model was tested on 20 major flood events (inflows above 500 m³/s) from 2016 to 2020. The main goals were to reduce downstream flood peaks and maintain high reservoir storage post-flood to ensure water availability for hydropower and dry season water demand. For example, during the 2020 flood event, the optimized strategy reduced the flood peak at the Song Tranh 3 control point by 17% (from 2,688 to 2,230 m³/s) while restoring the reservoir to normal water levels. By ensuring downstream safety and optimizing power generation, this advanced technique not only supports decision-making but also boosted economic efficiency, with an additional 62 million JPY in hydropower revenue recorded during the 2020 flood event.