西平县小洪河2020年7·22洪水分析

Analysis and Reflections on 7·22 Flood of 2020 in Xiaohong River of Xiping County

小洪河与上中游水库群、西平县杨庄滞洪区、西平县老王坡滞洪区是淮河防洪体系重要组成部分,小洪河防洪工程联合运用承担了豫南防汛工作中重点防洪任务,自2008年来未发生洪水过程,西平县小洪河城区段通过城市水系治理工程,行洪能力有了很大提高;对2020年7月21日至23日发生在小洪河流域大到暴雨产生的小洪河洪水,进行降雨、洪水过程、洪水量级、洪水传播时间、工程防洪调度等方面分析;发现上游水库调度对7·22洪水产生很大影响,7·22洪水中小洪河桂李站实测最高水位和最大流量与保证水位、流量关系存在异常现象;提出水库工程防洪调度运用防洪库容全部拦蓄原则,建议调整小洪河桂李站防汛特征水位,为小洪河流域洪水精准调度提供基本依据。

Xiaohong River and the reservoir group in its upper and middle reaches together with the Yangzhuang flood detention area of Xiping County,and the Laowangpo flood detention area of Xiping County are important components of the flood control system of Huaihe River.The joint application of Xiaohong River flood control project has undertaken the key flood control tasks in the flood control work of southern Henan Province.Since 2008,the flood discharge capacity has enhanced remarkably with its urban water system treatment project.In this paper,the flood occurred in the Xiaohong River Basin on July 21-23,2020 induced by heavy rain and rainstorm was analyzed from the aspects of rainfall,flood process,flood magnitude,flood propagation time and project flood control operation.Results suggest that the operation of upstream reservoir has an apparent influence on the flood of July 22.Guili Station witnessed anomaly in the relationship between measured maximum water level and maximum discharge and the guaranteed water level and discharge.The principle of full detention of flood is suggested to adjust the characteristic water level of Guili Station for flood control.The research finding offers a basis for precise flood management in the Xiaohong River basin.