Numerical Simulation Of Urban Waterlogging In Xiamen University Region During Strong Typhoon Meranti

In this study,SWMM model and GIS technology are used to study the theory and technology of numerical simulation of urban rainstorm and waterlogging.Taking Xiamen University as an example,based on the basic data of geographic information and urban drainage network,constructing the SWMM model of the study area,using clustering analysis and random forest algorithm to calibrate parameters and verificate model.Finally,the Storm Waterlogging situation during the strong typhoon Meranti was simulated and reconstructed,and the disaster caused by typhoon rainstorm was evaluated.The results of this study are as follows:(1)Constructing the Urban Rainstorm and Waterlogging Simulation Model in Xiamen University region.In this study,the basic data of the study area were processed by GIS technology,and extracting and localizing the parameters needed for the model to complete the construction of the SWMM model.(2)Using cluster analysis algorithm to calibrate parameters.In this study,cluster analysis algorithm is used to classify the catchments according to the parameter settings of the verification point.And then,adjusting the parameters to improve the accuracy of the results.The errors between simulation results and measured data after parameter calibration are acceptable,which indicates that the method is suitable for model parameter calibration.(3)This study improves and optimizes the existing problems of surface water inundation analysis algorithm.The improved algorithm can effectively avoid repetitive calculation when water diffusion occurs.Considering the continuity of the flow,it begins to diffuse in the area with large accumulation of confluence,reducing the influence of abnormal values and pseudodepressions in DEM data on water diffusion.From the optimization results,the improved algorithm has a good effect.(4)Simulating and reconstructing the Storm Waterlogging situation during the strong typhoon Meranti.In this study,the observed rainfall data from 22:00 on September 14,2016 to 10:00 on September 15,2016 were used to simulate the development and change process of waterlogging.In addition,the overflow condition of inspection wells during the sub-typhoon storm,and the infrastructure in the flooded area was evaluated.Finally,estimating the disaster induced rainfall distribution under different depth of flooding.