Approach for appraising spate risks in urban drainage systems using stormwater management model

Urban inundation is a serious challenge that increasingly face the residents of many cities, as well as policymakers. Accordingly, inundation assessment is becoming increasingly momentous around the world. This comprehensive evaluation involves numerous indices in urban catchments, but the high-dimensional and non-linear relationship between the indices and the risk presents a tremendous challenge for accurate evaluation. In this study a project based on Stormwater Management Model (SWMM), Kriging and k-means clustering was used for quantitative and qualitative flooding risk assessment in urban drainage system over the western part of Kerman city. Flooding risk in the drainage system over the study area was evaluated by various precipitation scenarios and required parameters were calculated by land use map, DEM and field study. For calibration and assessment of model, calculated runoff in 3 point was measured and was compared with simulated runoff.Results show that,the proposed approach can identify the main driving factors, i.e., inundation duration, largest water flow and total flood amount in this study area. The inundation risk of each node can be qualitatively analyzed and quantitatively calculated. There are 3, 10, 13, 23, 30, and 33 node at risk under the return periods of 1-year, 5-years, 10-years, 20-years, 50-years and 100-years, respectively. This study proposes a novel and successful approach to assessing risk in urban drainage systems and provides guidance for improving urban drainage systems and inundation preparedness.