Optimal operation of the Three Gorges Reservoir subject to the ecological water level of Dongting Lake

Due to simultaneous impoundment of reservoirs on the Yangtze River, the water level of Dongting Lake has decreased in recent years, which has threatened the health of the lake's ecosystem. To mitigate the adverse effects resulting from conventional reservoir operation, an ecologically oriented reservoir optimization model was developed to maintain the water level of Dongting Lake as close as possible to the ecological water level while simultaneously maximizing hydropower production from the Three Gorges Reservoir (TGR). The relationship between the water level of the lake and the amount of water released from the reservoir was modeled using the support vector regression method, and the bi-objective optimization model was solved using the chaos-genetic algorithm. The applicability of the model was demonstrated in a case study of the TGR considering five regulatory scenarios. Relative to conventional operation, the numerical results indicate that the proposed optimized operational schemes could increase the hydropower production of the TGR while maintaining a water level near the EWL in Dongting Lake.