ABSTRACT
With the gradual increase in urbanization rate and people’s activity area, the change of land use type leads to the increase of imperviousness and thus the increasing problem of urban flooding. In this paper, a hierarchical index system combining SWMM and GIS simulation with hierarchical analysis (AHP) is proposed to assess urban flooding risk. Taking Dujiangyan as an example, it is divided into 154 sub-catchment areas in GIS using Tyson polygons for urban flood risk assessment. Finally, the risk values obtained were entered into the GIS, the 154 areas were divided into 5 risk levels, and different colors were used to represent the study area to show the magnitude of risk in the study area so as to visualize the risk.
