三峡水库汛前水位集中消落调度方式优化研究

Study on optimization of pre-flood water level centralized flow control mode of Three Gorges Reservoir

摘要

【目的】受来水预报不确定性及发电调度、生态调度试验、库岸稳定要求等影响，三峡水库的集中消落期调度方式存在水位精准调控困难、水资源利用效率有优化空间等问题。为了在有效控制防洪风险的同时提高三峡水库汛前水位集中消落期调度灵活性和综合效益，提出了延长三峡水库汛前集中消落期的优化调度方式。【方法】在分析三峡水库消落期水文情势变化情况的基础上，通过耦合延长三峡水库汛前集中消落、三峡水库调洪计算、下游河道洪水演进模型，对比分析了遭遇不同类型洪水时不同汛前水位集中消落方案的防洪影响和效益，以不影响防洪安全、有效提高综合效益为原则优选汛前水位集中消落方式。【结果】结果显示，延长三峡水库集中消落期3~5 d,遭遇1954年、1998年等长江流域实际大洪水时，三峡水库均可在转入防洪调度时将水位预泄至145 m,且预泄过程中，不增加下游沙市、城陵矶等主要水文站超警戒水位的天数，不抬高洪峰时沙市、城陵矶等主要水文站水位。【结论】结果表明：在防洪风险可控的前提下，6月中下旬在下游河道水位较低时，适当延长三峡水库汛前水位集中消落至145 m的时间，可以较好地统筹协调汛前防洪和供水需求，并有效衔接水库汛期运行水位动态控制，有利于提高集中消落期调度的灵活性和水资源利用效率，为三峡水库实际调度提供更好的条件。

Abstract

[Objective] Affected by the uncertainty of water forecast, power generation scheduling, ecological scheduling test, and bank stability requirements, the centralized water level scheduling mode of the Three Gorges Reservoir has some problems, such as difficulty in precise water level regulation and room for optimization of water resource utilization efficiency. In order to effectively control the flood control risk and improve the operation flexibility and comprehensive benefit, the optimal operation mode of extending the pre-flood period of the Three Gorges Reservoir was proposed. [Methods] Based on the analysis of the changes of hydrological regime in the Three Gorges Reservoir, the flood control effects and benefits of different schemes were compared and analyzed through the coupling of the extension of pre-flood centralized water level, the flood control calculation and the flood evolution model of the downstream river. Under the principle of not affecting the safety of flood control and effectively improving the comprehensive benefit, the pre-flood water level centralized subsiding method was optimized. [Results] The result show that the Three Gorges Reservoir can pre-discharge the water level to 145 m when it is transferred to flood control operation in 1954, 1998 and other major floods in the Yangtze River basin, and the pre-discharge process does not increase the number of days beyond the warning water level of major hydrological stations such as Shashi and Chenglingji downstream, and do not raise the water level during flood peak. [Conclusion] On the premise that the flood control risk can be controlled, when the downstream river water level is low in mid to late June, the pre-flood water level of the Three Gorges Reservoir can be appropriately extended to 145 m, which can better coordinate the pre-flood flood control and water supply needs, and effectively connect the dynamic control of the reservoir′s operating water level during the flood season, which is conducive to improving the flexibility of the centralized flood control and water resource utilization efficiency, and provide better conditions for the actual operation of the Three Gorges reservoir..

关键词

三峡水库 / 汛前集中消落 / 调度方式优化 / 长江流域 / 洪水 / 优化调度 / 多目标 / 洪水演进模型

Key words

Three Gorges Reservoir / centralized drainage before flood / scheduling mode optimization / Yangtze River Basin / flood / optimize scheduling / multi objective / flood routing model

基金资助

国家重点研发计划项目(2021YFC3200302)

中国长江三峡集团有限公司科研项目(799238)