基于MIKE模型的南丰景观坝行洪能力影响分析

近年来洪水引发的灾害日益凸显,造成的破坏持续增多,因此进行河道行洪能力影响分析对于加强河流的洪水管理及减少洪水带来的损失具有十分重要的意义。为评价南丰景观坝的防洪安全,基于MIKE水动力软件中的MIKE11、MIKE21模块,构建盱江南丰段的一、二维数值模型,对景观坝建设前后20 a一遇设计洪峰流量进行洪水模拟,然后选取河道水位和流场等指标的变化,分析景观坝的建设对研究河段河道行洪能力影响。研究结果表明,在20 a一遇洪水情况下景观坝上游壅水里程约3 km,且最大壅高约为0.1 m,同时两岸基本无漫堤险情;河道流态无明显变化,但局部流场产生发生一定变化,其中曾巩大桥等四座大桥桥墩处流速有不同程度的减小并产生局部回流,景观坝坝址处流速略有增大。

Analysis of flood discharge capacity of Nanfeng landscape dam based on MIKE model

In recent years，the disasters caused by floods increase prominent and the damage caused by floods continue to increase. Therefore，it is of great significance to analyze the impact of river flood discharge capacity for strengthening flood management and reducing the losses caused by floods. To evaluate flood control safety of Nanfeng sight dams，based on the MIKE 11 and MIKE 21 modules in the MIKE，we build the hydrodynamic numerical models of the Nanfeng section of Xujiang river，and simulate the peak flow every 20 years before and after the construction of sight dams. Then，we select the changes of water level and flow field to analyze the influence of the construction of landscape dam on the flood carrying capacity of the study river. The results show that the backwater of sight dams upstream is about 3 km and the maximum value is about 0. 1 m in the case of flood every 20 years. At the same time，there is no overtopping risk on banks. There is no obvious change in river flow，but the local flow field has some changes. Among them，the velocity at the piers of Zenggong bridge and other four major bridges decrease to some extent and produce local backflow，while the velocity at the dam site of landscape dam increase slightly.