Regional flood risk analysis for Huaihong south flood control protected area in China using an integrated method

Non-engineering flood control measures have gradually become an important part of flood disaster management in the past decades, and it cannot be separated from regional flood risk analyses. Flood risk analyses can be regarded as a complex of three aspects: flood hazard analyses, vulnerability analyses and comprehensive evaluation of both. In this paper, taking Huaihong South Flood Control Protected Area (simplified as HHS) of the Huaihe River Basin in China as an example, a one-dimensional (1-D) and two-dimensional (2-D) coupled hydrodynamic model of the study area was established to simulate the evolution process of the floods with different return periods and acquire inundation data in the flood hazard analysis. Concerning the vulnerability analysis, based on the composition mechanism of vulnerability and the available data of the study region, the vulnerability evaluation index system was established, then the magnitudes of vulnerability of the townships in the research were analyzed through the catastrophe progression method. Combined with the analysis results above, the flood risk of 15 townships in HHS can be classified into 6 magnitudes by factor analysis and hierarchical clustering analysis. The results show that the flood risk is medium or even higher in most zones of HHS. The integrated method used in this research can also be applied to other regions.