Research on optimal water scheduling strategies for cascade reservoir groups considering decision-making preferences

Abstract

[Objective] Global climate change, population growth, and intensified social activities have led to variations in the spatiotemporal distribution of water resources, posing challenges to the development and utilization of water resources. Optimizing the water scheduling of cascade reservoir groups is crucial for water resource allocation. However, current research lacks sufficient consideration of decision-makers' preferences for water shortage patterns and time.[Methods] To address the challenges in water resource allocation, an optimal water volume scheduling model for cascade reservoir groups was established with the primary objective of minimizing water supply deficits. Three water shortage pattern strategies—total water supply deficit control, centralized distribution, and wide-shallow distribution—were proposed, along with water shortage time strategies that adjusted weights across different periods. Then, an analysis was conducted using the Toutun River Basin as a case study.[Results] In the case study of water shortage pattern strategies, when the inflow frequency was p=50%, the wide-shallow distribution pattern result ed in the smallest supply deficit(493 700 m³), the centralized distribution pattern result ed in the largest deficit(1 797 400 m³), and the total water supply deficit control pattern fell in between(973 300 m³). When the inflow frequencies were p=95% and p=75%, although the total supply deficits under the three patterns were similar, the water shortage was more evenly distributed under the wide-shallow distribution pattern. In the analysis of the water shortage time strategy, using p=95% as an example, after applying the strategy, the water supply deficits in March to May decreased from 58 400 m³, 5 735 800 m³, and 6 246 600 m³ to 49 000 m³, 134 000 m³, and 124 600 m³, respectively. However, the deficits in other months increased from 32 496 200 m³ to 44 223 200 m³, and the total water supply deficit remained essentially unchanged.[Conclusion] In summary, the proposed strategies are proven effective. The wide-shallow distribution pattern demonstrates clear advantages in ensuring supply stability. The water shortage time strategy can reduce water supply deficits in specific periods, but it does not reduce the total deficit—it only redistributes the time of the shortage. The findings can serve as a reference for water allocation of cascade reservoir groups.

Keywords

cascade reservoir group / water volume scheduling / decision-making preferences / water shortage pattern strategy / water shortage time strategy / influencing factors