再论水库汛期水位动态控制的必要性和可行性

汛限水位是水库在汛期允许兴利蓄水的上限水位,在防洪中具有法定地位,是协调水库防洪与兴利的关键参数,直接影响水库效益发挥。近年水利和应急管理部门落实强监管措施的过程中,出现了强制要求水库汛期不超汛限水位的情况,导致相当多的水库汛期过度弃水、汛后无水可蓄。我国许多省份发生干旱时出现无水可供的困局,2022年长江流域历史性特大干旱情况尤甚。本文通过回顾汛限水位动态控制试点工作,论述汛限水位设置依据和实际监管中存在的问题,阐述开展汛期水位动态控制的必要性和可行性;归纳总结梯级水库运行期设计洪水、分期汛限水位和汛期水位动态控制的理论及方法;提出需要继续深入研究的科学问题和关键技术;最后建议加强水利工程基础措施建设,修改完善现有的法律法规和设计洪水计算等规范,建立符合新阶段水利高质量发展的运行机制,统筹协调防汛抗旱和洪水资源高效利用,实现水库汛期水位动态控制。

Revisiting necessity and feasibility for dynamic control of reservoir water level during flood season

According to the national flood control act of China, the flood-limited water level (FLWL) defined as the upper boundary of reservoir impoundment operation during flood season, is a key parameter to tradeoff between flood prevention and conservation operation, which affects reservoir comprehensive utilization benefits. In recent years, both the water resources and emergency government sections in China excessively tended to pursue the FLWL during flood season, which leads to both low flood utilization rates and reservoir refill rates. Many regions have suffered the shortage of the water supply in dry season, especially in the Yangtze River basin encountered a historical severe drought in 2022. This study reviewed the experimental work on dynamic control of reservoirs'' FLWL, clarified the basis for setting the FLWL and the drawbacks in the process of FLWL supervision and management, elaborated on the necessity and feasibility of dynamic control of reservoir operational water levels, summarized the theory and methods of the design flood estimation for cascade reservoirs, seasonal FLWLs, and dynamic control of FLWLs, proposed the key technical and scientific issues of the related research domain. Finally, we suggest to strengthen the capacity building of hydraulic infrastructure, to revise and improve current flood control act and regulations as well as design flood guidelines, to establish the operating mechanism corresponding to high-quality development of water resources, to coordinate the flood prevention and drought relief, and to realize dynamic control of reservoir water levels and high-efficient flood utilization.