Presenter
Dr. Xin Wang, Hubei Water Resources Research Institute, Wuhan, China; Hubei International Irrigation and Drainage Research and Training Center, Wuhan, China
Co-author(s)
Prof. Tiesong Hu, Wuhan University
Prof. Xiang Zeng, Wuhan University
Dr. Fengyan Wu, Hubei Water Resources Research Institute
Dr. Jianan Qin, Hubei Water Resources Research Institute; Hubei Water Saving Research Center, Wuhan, China
Sub-theme
5. Establishing Sustainable Water Infrastructures
Topic
5-6. Multi-functional utilization of water projects, including hydropower stations
Body
As achieving carbon neutrality underscores the role of hydropower for stable utility of renewable energy, managing the rivalry between flood control and hydropower generation is becoming more essential for optimizing multipurpose reservoir operation. However, current optimization models, which mainly describe the relationship between flood safety and power production as a “rise and fall” competition, are challenged by the complex, multi-level institutional structure and ill-posed issue in practice. Particularly for reservoir impoundment, given the flood control rules set by the upper-level department, the water conservation sector at the lower-level could choose multiple refill rules for maximizing hydropower generation, while these refilling plans may lead to dissimilar levels of flood risk (i.e., ill-posedness of the problem). In light of this, optimizing reservoir operation is not merely a trade-off problem but involves promoting cooperation of the water conservation sector with the flood control department, namely selection of a refilling plan in favor of flood safety. Therefore, the main goal of this study is to (1) explore the cooperation potential in reservoir operation problems with hierarchical decision-making structure and ill-posed characteristic and (2) develop a framework to derive the competitive-cooperative (i.e., co-opetition) strategy between flood control and water conservation departments. Having constructed the ill-posed bilevel programming model for the Three Gorges Reservoir early impoundment problem, the study incorporates two different asymmetric cooperative game approaches, weighted Shapley value and games with a permission structure, to formulate coordination mechanisms in the leveled structure. Multi-population particle swarm algorithm and parallel computing are applied to solve the optimization problem. Results illustrate that cooperation between two departments has the potential to reduce the flood risk in terms of average occupancy rate of flood control storage by 20% without sacrificing power generation benefits. Both co-opetition strategies based on asymmetric cooperative games have substantially reduced efficiency loss in the non-cooperative situation and achieve nearly Pareto optimality of the whole problem. On the other hand, distributions of cooperation benefits between two departments show considerable disparity. While the weighted Shapley value solution with weight ratio set as 0.6:0.4 decreases the flood risk by 12% and increases the annual power generation by 0.2 billion kWh, the game strategy with a permission structure leads to 45% lessened flood risk but a power production that is even smaller than the non-cooperative case. The findings suggest considering overall satisfaction of objectives as well as actual organization of authority when determining the co-opetition strategy.