A conflict resolution model for reservoir operation in dry seasons under channel alteration

Abstract

The increases in extreme drought events and channel alteration challenge the existing reservoir operation rules. Therefore, reservoir operation should be reconsidered to accommodate these challenges. A conflict resolution model for reservoir operation considering the decision-makers’ preference is developed for the conflict between hydropower generation and navigation in dry seasons under channel alteration, to achieve the goal of meeting minimum environmental flow, landslide stability, and river–lake connection constraints. This model with a nondominated sorting genetic algorithm-II (NSGA-II) is applied to the Three Gorges Reservoir (TGR) on the Yangtze River. The results show that minimum navigation discharge for the post-dam period is greater than that for the pre-dam period, indicating channel alteration. Both average hydropower generation benefit and navigation reliability decrease with modification of the post-dam minimum navigation discharge, signifying the adverse effect of damming. The total benefits of navigation and hydropower generation decrease with the exceedance probability. A higher hydropower generation benefit leads to a smaller navigation benefit, reflecting the conflict of interest. This study demonstrates the feasibility of the proposed conflict resolution model, as well as the navigation benefit-quantifying method and applicability to similar water resources management problems.