Multi-objective optimization scheduling for extensive plain lake water resources incorporating flood resource utilization
Yalei Han, Zengchuan Dong, Can Cui, Tianyan Zhang, Yun Luo
Abstract
Plain lakes are crucial water sources for regional development, but increasing hydrological changes and intensified human activities have exacerbated conflicts among their functions. This study focuses on Hongze Lake, significantly impacted by the South-to-North Water Diversion East Line Project, which elevated water levels and substantially altered regional water resource utilization, while flood management regulations have remained unchanged. To investigate the impact of adjusting flood limit water level on various functions of Hongze Lake, a multi-objective optimal scheduling model for water resources was developed, encompassing water supply, water diversion, navigation, and ecological conservation. This model was combined with a projection pursuit optimization model to solve the scheduling scheme set. Results reveal changes in competitive relationships within the non-dominated solution set following adjustments in flood limit water levels. Notably, water diversion volume increased by 1.591 billion m 3 and the ecological assurance rate improved by 5.92 %. However, there was a 0.46 rise in water supply deficit and a 3.84 % decline in guaranteed navigation rate. Multi-objective evaluation indicates a decreased importance of the ecological objective, while the importance of water supply and water diversion increased significantly. Optimal scheduling schemes resulted in an average water level rise of 0.18 m, increasing cumulative water storage by 266 million m 3 while ensuring flood control. It is demonstrated that the lake’s regulation and storage capacity are effectively improved by adjusting flood limit water level. This research provides a methodology for the utilization of flood resources and the management of water resources in lake-type reservoirs, with implications for balancing competing water demands.