Research On Urban Storm Waterlogging Simulation And Disaster Risk Assessment Based On SCS And GIS

With the rapid development of urbanization,urban waterlogging disasters have been becoming more and more obvious.Many important cities in the country present the phenomenon of "waterlogging is inevitable when it rains".Rainstorm waterlogging has brought great hidden dangers to the development of cities,and brought great damage to the safety of residents' lives and property.Urban waterlogging has become one of the key factors affecting the sustainable development of cities.In response to frequent urban waterlogging disasters in China,it is particularly important to study the process of rainfall,runoff yield and confluence and risk assessment,which is also an important part of urban flood control and disaster reduction.In this paper,hydrological model,spatial information technology,disaster risk assessment theory and other multi-disciplinary knowledge are used to construct urban waterlogging process simulation model and risk assessment model.Combing with research examples,urban waterlogging process simulation and risk assessment in different rainfall recurrence periods are carried out.The main results and conclusions of this paper are as follows:(1)Based on the formula of storm intensity,Chicago rainfall process line model,SCS(Soil Conservation Service)runoff yield model and GIS-based local equal volume submergence method,the simulation model of urban waterlogging process is constructed.Taking the Tangxun Lake Basin in Wuhan as an example,the urban waterlogging process of 5,10,20,30 and 50 years with different rainfall recurrence periods was simulated.The results show that the accumulated water produced by rainstorms in different rainfall recurrence periods mainly distributes around major lakes.With the increase of rainfall recurrence period,the submerged area enlarges in a planar manner to the surrounding area.The higher the height of the flooded water,the wider the submerged area is.The simulation results can be used as risk factor data for urban waterlogging risk assessment.(2)Based on the analysis of urban waterlogging disaster system and its influencing factors,the risk assessment factors of urban waterlogging disaster are determined.The data of risk assessment index are processed and acquired by spatial data analysis method.The risk assessment model is further combined to analyze the risk of disaster-causing factors.From three aspects of environmental sensitivity of disaster pregnancies and vulnerability of disaster-bearing bodies,a comprehensive risk assessment of urban waterlogging disasters was conducted in the study area of Tangxun Lake Basin.The results show that the high-risk areas of urban waterlogging disasters are mainly located in the northern part of the basin,around larger lakes,and the boundary areas of the basin;the lower-risk areas are mainly located in the southern part of the basin,where the vegetation coverage is more intensive,the water system is smaller,and human activities are relatively less,so they are not vulnerable to urban waterlogging.The simulation of urban waterlogging process and its risk assessment are important non-engineering measures for urban flood control and disaster reduction.Multidisciplinary knowledge such as hydrological model,spatial information technology,disaster risk assessment theory and so on is a powerful means to carry out urban waterlogging process simulation and urban waterlogging disaster risk assessment.The results of this study are convenient to intuitively grasp the risk situation of urban waterlogging,and provide technical guidance for the formulation of urban flood control and disaster reduction plans and countermeasures.