A multiscale risk operation and decision making model for inter-basin water diversion project under climate...

Inter-basin water diversion projects are crucial for mitigating the spatial imbalance between water supply and demand. However, their operation is challenged by complex uncertainties arising from climate variability and hydrological fluctuations. To address these challenges, this study develops a multi-objective risk operation model and decision-making model for inter-basin water diversion projects. At the operational level, a multi-objective risk operation model is formulated to minimize both the total water shortage in water-receiving regions and the total transfer cost at pumping stations, while explicitly accounting for forecast uncertainties in source water availability. The model is solved by the Multi-Objective Mantis Search Algorithm (MOMSA) to generate a set of non-dominated solutions. At the decision level, a comprehensive risk decision-making model is established by integrating the Kemeny Median Indicator Ranks Accordance (KEMIRA) framework with the Best-Worst Method (BWM) for expert input and Data Envelopment Analysis (DEA) for dynamic weighting. The proposed framework is applied to the "One Gate Three Lines " project, a major water diversion project in China. The results show that non-dominated solutions under uncertainties effectively encompass the deterministic solution space. Compared with the deterministic case, the average water shortage rate reduces by 1.92 %, while the average transfer cost increased by CNY 63,300 due to uncertainty considerations. The risk decision-making model effectively captures multiscale risks and supports adaptive, risk-informed decision making for inter-basin water diversion operations under climate variability.