2023年里下河地区暴雨洪水分析

Analysis of Rainstorm and Flood in the Lixiahe River Region in 2023

里下河地区地势平缓,河网错综复杂,水势传播较慢,易发生超警戒洪水过程。为研究里下河地区梅雨期降雨特点,采用皮尔逊Ⅲ型频率曲线法、距平分析法和降雨水位逐时过程图法,针对里下河地区2023年梅雨期暴雨洪水过程,通过与历史梅雨期降雨进行对比,全面分析了里下河地区梅雨期暴雨洪水特征。结果表明,里下河局部地区无降雨与极端降雨情况并存,在最大1天降雨中存在特大暴雨,最大3天降雨中出现特大暴雨的地方占8.4%。短时间强降雨加上里下河地区河网地势特征是发生超警戒洪水过程的主要原因。洪水过程下沿江抽排及五大港抢排对里下河地区水位变化有较明显影响。

The Lixiahe river region boasts a flat terrain,a complex river network,and a water regime that spreads slowly,making it susceptible to super-alert flood process.In order to study the characteristics of rainfall during the Meiyu period in 2023,Pearson III frequency curve method,anomaly analysis method and hourly process chart method of rainfall level were used to analyze the storm flood characteristics by comparing the rainfall during the historical Meiyu period.The conclusion is that there is no rainfall and extreme rainfall in some areas.There is an extremely heavy rainstorm in the maximum one-day rainfall,and 8.4%of places have an extremely heavy rainstorm in the maximum three-day rainfall.The short duration high intensity rainfall process and topography of river network in the Lixiahe river region are the main reasons for occurrence of super-alert flood process.The drainage along the river and five major ports has a significant impact on the water level changes in the Lixiahe river region during the flood process.