Research On Multi-scenario Waterlogging Risk Assessment Based On Entropy Weighting And GIS

With the acceleration of urbanization in recent years,the severity and frequency of urban rainstorm show a trend of continuous increase,and the flood frequency and damage caused by the corresponding urban rainstorm are also significantly intensified.The flood disaster has become one of the important reasons hindering the healthy and sustainable development of cities.In order to provide scientific theoretical basis for urban waterlogging management,water ecological civilization and waterlogging disaster prevention mechanism in China,it is necessary to analyze the cause mechanism of urban waterlogging and evaluate the risk of waterlogging.The main research contents and achievements of this paper are as follows:(1)The comprehensive analysis of the causes of waterlogging disasters from the four perspectives of nature,social and economic development,urban construction and disaster warning provides a basis for the construction of a provincial waterlogging and disaster reduction capacity assessment system,the development of the provincial waterlogging and disaster reduction assessment theories and methods.(2)The basic principles and methods of the entropy-weighted TOPSIS method and principal component analysis method for the assessment of provincial flood prevention and disaster reduction capacity were discussed.The entropy-weighted TOPSIS method was used to improve the principal component analysis method.The theoretical system for the assessment of the ability of preventing floods and mitigating disasters at the provincial level has been established.(3)Twenty five evaluation indicators were screened out to comprehensively evaluate the waterlogging and disaster mitigation capabilities of 31 provinces with the entropy-weight TOPSISI-PCA coupled optimization evaluation model.Water logging and disaster mitigation capabilities of 31 provinces were analyzed.(4)A one-dimensional and two-dimensional coupled drainage model is established to obtain hazard data of hazards in the fuzzy comprehensive evaluation model.After calibrating and verifying the model,the operation status of the pipeline network and nodes in the study area for the low-recurrence period rain analysis of 1a to 5 a was designed.Water depth,time,and area in the study were obtained through the heavy rain period simulation of 10a to 100a,which provides a basis for subsequent flood risk assessment.(5)The grid calculator tool is used to realize the matrix solution process of the fuzzy comprehensive evaluation model.The grid unit and the catchment unit are used as the evaluation unit to superimpose the raster layers.Finally,the distribution map of rainstorm waterlogging risk in the study area in 50 years was obtained.The results show that the overall risk distribution is high in the middle and low in the periphery.The areas with high and low risks occupy the largest area.The high-risk areas are mainly distributed in the Xinhua Road area,the intersection of Jianshe Street and Bohai West Road,and the Xinhai East Road area.And Yingbin Street Industrial Zone is more in line with the actual situation.According to the results of waterlogging risk assessment in the study area,a series of waterlogging disaster prevention measures are proposed from the perspective of urban construction and disaster warning to provide theoretical guidance for improving the urban waterlogging prevention and mitigation system...