韩江南北堤防洪保护区溃坝洪水演进数值模拟研究

Numerical modeling of dam-break flood in the Hanjiang River Flood Protection Area

洪水分析计算是洪水风险图编制的基础。基于一维、二维水力学耦合模型,建立了韩江南北堤防洪保护区溃坝洪水演进数学模型,分析探讨了韩江南北堤瞬溃后溃口流量水位关系、主要地物特征点的水位和流速变化以及洪水演进过程。结果表明:溃口峰值流量出现在溃坝瞬间,随外江水位下降,溃口流量减小,至溃坝99 h后基本为0。湘桥区距溃口最近,受洪水破坏最严重,最大流速值超过1. 3 m/s。云路镇、登岗镇和湘桥区由于地势较低,最大淹没水深普遍在2 m以上。

The flood calculation is based on flood risk map.In this paper,a 1D and 2D coupling numerical model of the Hanjiang River Flood Protection Area is established to evaluate the relationship between flow rate and water level,the water level and velocity of the feature points,the dam-break flood routing process.The results showed that the dam-break peak flow appears the largest at the beginning of the dambreaking,as the water level in the reservoir falls gradually,the flow discharge decreases linearly from the top to zero till the 99h after dam breaking.The dam-break flood has a greater destructive power against the area at Xiangqiao district where the maximum velocity can be faster than 1.3m/s.Yunlu town,Denggang town and Xiangqiao district where the maximum inundated depths can be deeper than 2m due to the lower terrain.