Risk-benefit decision evaluation of flood control operation based on subjective-objective integrated weighting

To address the decision-making problem of flood control scheduling schemes for complex water projects, a subjective and objective integrated weighting risk-benefit evaluation and decision-making model based on AHP-CRITIC-TOPSIS was proposed. Taking the flood control scheduling simulation of the Yangtze River Basin from July 28 to August 3, 1954 as an example, a flood control scheduling risk-benefit index system was constructed. The AHP-CRITIC method was used to achieve the collaborative optimization of index weights in a "experience-oriented - data-driven" manner, and the TOPSIS method was applied to the evaluation of the regulation effect of the joint flood control scheduling schemes of water projects. The results show that there is a game among the risk-benefit indicators, with the weight of the affected population indicator reaching the maximum of 0.2513. The combined weight better integrates the expert decision-making preference experience. Compared with Scheme 1, the recommended optimal Scheme 3 reduces the excess flood volume downstream by 5 billion cubic meters, the affected population by 1.208 million people, and the inundation loss by 23.2 billion yuan at the cost of reducing the flood control capacity by 7.63 billion cubic meters. The research results can provide reference for evaluating the regulation effectiveness and optimizing schemes in joint flood control scheduling of complex water engineering projects.