在建水库蓄水滞洪对流域联合防洪方式的影响

Impact of water storage and flood detention by reservoirs under construction on joint flood control methods in river basins

摘要

【目的】针对水库施工期蓄水阶段的滞洪效应与梯级水库防洪调度协同问题，探索在建水库蓄水与已建梯级水库防洪库容的动态分配机制，以提升洪水资源化利用效率并实现防洪安全与发电效益协同优化。【方法】以雅砻江梯级水库为对象，构建梯级水库联合调度模型，基于典型年设计洪水，采用马斯京根法推演洪水过程，结合两河口水库蓄水期约束条件，量化两河口水库蓄水量与下游锦屏一级、二滩水库防洪库容的等效比例。【结果】结果显示：两河口水库初期运行期(2022年)蓄水目标为2 835 m时，可等效置换下游梯级水库防洪库容15.92亿m³,在保障流域防洪安全(防洪库容≥25亿m³)前提下，梯级水库综合可利用库容动态调控范围达26~42亿m³;实际调度中，通过梯级水库联合调度，抬高了下游锦屏一级、二滩水库运行水位，避免了水库弃水。【结论】结果表明：将施工期水库蓄水滞洪作用纳入梯级水库联合防洪调度体系，通过优化蓄水进程可提升洪水资源利用率，实现防洪安全与发电效益协同，为保障供电供水奠定良好的水量基础，并为流域在建水库施工期蓄水阶段的联合防洪调度提供科学依据与工程示范。

Abstract

[Objective] To address the flood detention effect during the impoundment phase of reservoirs under construction and the coordination of flood control scheduling among cascade reservoirs, and to explore a dynamic allocation mechanism between impoundment in under-construction reservoirs and flood control storage capacity in existing cascade reservoirs to improve the efficiency of floodwater utilization and achieve coordinated optimization of flood safety and power generation benefits. [Methods] Taking the Yalong River cascade reservoirs as the study subject, a joint scheduling model for cascade reservoirs was developed. The Muskingum method was applied to simulate the flood process based on the design flood of a typical year. Combined with the storage constraints during the impoundment period of the Lianghekou Reservoir, the equivalent ratio between the impoundment volume of the Lianghekou Reservoir and the flood control storage capacities of the downstream Jinping I and Ertan Reservoirs was quantified. [Results] The result showed that when the Lianghekou Reservoir aimed for an impoundment level of 2 835 m during its initial operation period(2022), it could effectively replace 1.592 billion m³ of flood control capacity in the downstream cascade reservoirs. Under the premise of ensuring flood control safety in the basin(flood control capacity≥2.5 billion m³), the dynamic regulation range of the total usable capacity of the cascade reservoirs could reach 2.6~4.2 billion m³. In actual scheduling, joint operation of the cascade reservoirs raised the water levels of the downstream Jinping I and Ertan Reservoirs, thereby avoiding reservoir water spillage. [Conclusion] The result show that the flood detention effect during the impoundment phase of reservoirs under construction can be incorporated into the joint flood control scheduling system of cascade reservoirs. By optimizing the impoundment process, the floodwater utilization efficiency can be improved, and flood safety and power generation benefits can be coordinated. It provides a solid water resource foundation for ensuring power and water supply security, as well as scientific support and an engineering demonstration for joint flood control scheduling during the impoundment phase of under-construction reservoirs in the basin.

关键词

在建水库 / 蓄水滞洪作用 / 联合防洪方式 / 洪水资源化 / 影响因素

Key words

reservoir under construction / water storage and flood detention effect / joint flood control method / floodwater utilization / influencing factors

基金资助

国家自然科学基金长江水科学研究联合基金(U2340213)

雅砻江流域水电开发有限公司科研项目(YLDC-JKA-ZZ2023200)