基于MIKE FLOOD的中小河流溃堤洪水风险分析

近年来洪水引发的中小河流堤防溃决等洪水灾害风险问题凸显,因此进行溃堤洪水风险分析对于加强中小河流的洪水管理及减少溃堤洪水带来的损失具有十分重要的意义。以江西省罗塘河为例,借助MIKE软件中的MIKE 11、MIKE 21及其耦合模块对罗塘河遭遇10a一遇及20a一遇洪水进行溃堤洪水演进模拟。然后依据灾害系统理论从洪水的危险性和易损性两方面选择淹没水深、淹没流速、淹没历时等7个指标构建溃堤洪水风险评价指标体系。最后利用GIS技术与层次分析法对罗塘河洪水风险进行了评价。结果表明:洪水危险区面积为0.19 km~2,占研究区总面积的2.18%,主要分布在地势低洼的富港地区;重灾区和中灾区面积为1.25 km~2,占研究区总面积的14.37%,主要分布在重文和蒋元乐家;安全区为研究区域内洪水没有到达并且地物覆盖价值较低的地区,包括游家店、下胡、大塘杨家和马山等处。研究成果可为中小河流防洪规划、避洪转移等提供参考依据。

Risk assessment of floods of dike-break in medium and small rivers based on MIKE FLOOD

In recent years，flood disasters caused by floods in small and medium-sized rivers have become more prominent. Therefore，the risk analysis of flooding and flooding is of great significance for strengthening flood management of small and medium-sized rivers and reducing losses caused by flooding. Taking Luotang River in Jiangxi Province as an example，Used MIKE 11、MIKE 21 and its coupling module in MIKE software to simulate the flooding evolution of the Luotang River. Then according to the hazard system theory，seven indicators including submerged water depth，submerged flow velocity and submerged duration were selected to construct the flood risk assessment index system. Finally，the GIS technology and analytic hierarchy process were used to evaluate the flood risk of Luotang River. The results show that the area of flood danger zone is 0. 19 km2 ，accounting for 2. 18% of the total area of the study area，mainly distributed in the Fugang area; the area of the severely affected area and the disaster-stricken area is 1. 25 km2 ，accounting for 14. 37% of the total area of the study area，mainly distributed in Chongwen and Jiang Yuanlejia; the safe area is the area where the floods have not arrived in the study area and the value of the land cover is low，including Youjiadian，Xiahu，Datang Yangjia and Mashan. The research results can provide reference for flood control planning and flood diversion of small and medium-sized rivers.