Research And Application Of Dynamic Assessment Model Of Waterlogging Disaster Risk In Xi'an

Affected by global climate change,extreme weather events have become more sudden,frequent,and widespread.The frequency and intensity of natural disasters have increased all over the world,which has become an important factor affecting rapid economic development and social harmony and stability.Urban waterlogging disaster is one of the most harmful natural disasters at present,which has a great impact on urban development,people's travel,property safety and so on.In recent years,Xi'an has suffered from rainstorms and waterlogging disasters,which has had a serious impact on the production and life of urban residents.Risk assessment of flood disasters can provide reference basis for flood control and disaster reduction.This paper takes the main urban area of Xi'an as the research area.Firstly,the typical waterlogging events in the main urban area of Xi'an were sorted out,the causes of waterlogging were analyzed and the risks of waterlogging disasters were identified.Secondly,the risk assessment index system was established,and the risk assessment model of waterlogging disaster was established based on matter-element extension method.Finally,the urban waterlogging dynamic risk assessment system was designed and developed,and the system was applied based on the data of Xi'an in 2018.The main research conclusions are as follows:(1)The waterlogging risk assessment model based on matter-element extension is established.The factors of waterlogging disaster are identified from the aspects of disaster-causing factors,disaster-preparing environment,disaster-bearing bodies and disaster prevention and mitigation capabilities.Combined with the characteristics of urban waterlogging disasters,the principle of index selection is determined to construct a reasonable and feasible index system.The weight of each index is determined by the method of combining AHP and entropy weight method.And the risk assessment model of urban waterlogging disaster is established based on matter-element extension method.(2)The risk of waterlogging disasters in Xi'an is carried out.Based on the risk assessment model and combined with the actual situation of Xi'an,four first-class indicators and fourteen second-class indicators are constructed including rainfall,topography,land use,population,economy and so on.The weight of all indexes are calculated,among which three indexes of rainfall,ground elevation and road network density are higher weight.Based on the assessment model,waterlogging risk assessment in the main urban area of Xi'an is carried out.The results show that Beilin,Xincheng and Lianhu are of high risk grade,Weiyang and Yanta are of lower risk grade,and Baqiao is of low risk grade.(3)A risk dynamic assessment system of urban waterlogging is developed.Based on the comprehensive integration platform,with knowledge visualization,component technology and data warehouse technology as technologies,the dynamic assessment system of urban waterlogging risk is established.The system takes the main urban area of Xi'an as the research area for assessment and realizes the dynamic assessment of urban waterlogging risk.The system construction process is convenient and flexible,and can be adjusted for different situations.The whole assessment process is visible and credible,which improves the efficiency of the assessment process and the credibility of the assessment results.