珠江流域2022年暴雨洪水分析

An Analysis of Storm Flood Occurring in the Pearl River Basin in 2022

2022年珠江流域暴雨洪水范围广、强度大、持续时间长。为了分析此次暴雨洪水成因,比较其与历史相似洪水的异同,从而进一步掌握珠江流域暴雨洪水规律并为流域防汛抗洪工作提供参考,分析了2022年珠江流域暴雨洪水特性,概述了致洪暴雨的天气背景、降雨过程,重点从洪水过程、洪水组成、水利工程作用、与历史暴雨洪水比较等方面进行了分析总结。结果表明:2022年5月下旬至7月上旬,珠江流域累计面降雨量较常年同期偏多5成,其中北江、韩江均为1961年以来同期最多;受其影响,珠江流域接连发生2次流域性较大洪水、8次编号洪水,其中北江发生1915年以来最大洪水;采用中国洪水预报系统进行洪水组成分析,西江干流洪水以红水河、柳江、郁江、桂江来水为主,不同场次洪水洪量占比不同,北江干流洪水以连江来水为主,其次为区间产流,韩江干流洪水主要来自于梅江和汀江;经与2005年、2008年历史大洪水对比,2022年珠江流域暴雨历时明显偏长,且暴雨中心位置偏西偏北,洪水过程次数也明显偏多,2022年北江洪水量级为特大洪水,大于2005年和2008年,但西江洪水量级明显小于2005年和2008年。在应对此次洪水过程中,流域防洪工程联合调度运用防洪效益十分明显,有效避免了西江、北江洪水恶劣遭遇,确保了重要地区防洪安全。

In 2022,the Pearl River Basin underwent extensive,severe and protracted rainstorms and floods.This study investigates the causes of this event,compares it with historical floods,and exemplifies the patterns of rainstorms and floods in the Pearl River Basin.To this end this study first presents the meteorological context and precipitation events leading to the flood.It then examines the flooding process,flood composition,the impact of water conservancy projects and comparisons with past rainstorms and floods.The results reveal that cumulative rainfall in the Pearl River Basin from late May to early July in 2022 was 50%higher than a normal year,with the Beijiang and Hanjiang River Basins experiencing the highest levels since 1961.The Pearl River Basin endured two major floods and eight numbered floods due to persistent heavy rainfall,with the Beijiang River encountering the largest flood since 1915.Flood composition analysis using national flood forecasting system of China shows that the primary inflow for the Xijiang River originates from the Hongshui River,Liujiang River,Yujiang River and Guijiang Rivers,with different flood volume proportions for each flood.The Beijiang River’s primary flood comes from the Lianjiang River,followed by the interval flow,while the Hanjiang River’s main flood arises from the Meijiang and Ting Rivers.In comparison with the 2005 and 2008 rainstorms and floods,the 2022 rainstorm duration was longer and had more floods.Moreover,the flood magnitude of the Beijiang River in 2022 was a heavy flood,which was more severe than that in 2005 and 2008,while the flood magnitude of the Xijiang River was less severe.The coordinated operation of flood control projects in the basin achieved significant flood control benefits,during this flooding process,preventing the simultaneous occurrence of severe floods in the Xijiang and Beijiang Rivers,and effectively ensuring the flood control safety in crucial areas.