Multilayer entropy-weighted TOPSIS method and its decision-making in ecological operation during the subsidence period of the Three Gorges Reservoir

Coordinating the downstream ecological demand and the power generation demand of hydropower stations is an important task in the operation of reservoirs, and how to evaluate the ecological satisfaction of the scheduling process is a difficult problem that needs to be solved urgently. A multi-objective optimal reservoir scheduling model was constructed to coordinate the spawning flow demand of " Four Major Chinese Carps"; The model takes the maximum power generation and the maximum membership degree of downstream river ecological water demand as the objective functions, and uses the dynamic programming multi-objective solution algorithm based on penalty factors to solve the problem, and obtains the non-inferior solution set in each scenario. The multilayer entropy-weighted TOPSIS method was used to study the non-inferior solution of the multi-objective scheduling model of the Three Gorges Reservoir, and the satisfactory solution ranking of the river flow rise process, ecological flow-related requirements, and power generation water requirements was obtained under the four schemes including 4d ~ 7d, which improved the reliability of the evaluation results and made up for the shortcomings of the traditional TOPSIS method in terms of hierarchy and weight science. The research results of this paper can provide a reference for decision-making on the ecological management of the spawning period of the " Four Major Chinese Carps" in the Three Gorges Reservoir of the Yangtze River.