Application of multi-criteria decision-making (MCDM) to support effective flood-season operation of the multi-reservoir system in the Ma River basin

Tóm tắt

Flood-season operation of multi-reservoir systems requires the simultaneous consideration of multiple objectives, including dam safety, downstream flood mitigation, carryover storage for the dry season, and hydropower generation. This study integrates HEC-ResSim simulation with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) to compare five operational alternatives for the Ma River Basin during the period from 1 July to 30 November 2025. The alternatives were developed by reducing the maximum pre-flood water levels at the Hua Na, Cua Dat, and Trung Son reservoirs by 0-2.0 m and were evaluated using nine quantitative criteria under eight weighting schemes representing different management priorities. The results show that the alternative involving a 2.0 m reduction in the maximum pre-flood water level provides the greatest downstream flood-mitigation effectiveness, but at the expense of reduced carryover storage for the dry season and hydropower generation. In contrast, the 0.5 m reduction alternative provides a relatively stable compromise and is more suitable when a balance among operational objectives is required. Overall, integrating MCDM with reservoir-operation simulation enables the trade-offs among competing objectives to be quantified, thereby directly supporting context-specific operational decision-making rather than prescribing a single fixed operating rule.