Urban Waterlogging Resilience Analysis And Study On Preventive Measures

In recent years,Chinese urban waterlogging disasters are serious.Urban waterlogging disasters restrict the healthy development of urban construction and threaten the safety of people's lives and property.In this context,it is necessary to study urban waterlogging.The birth and development of urban rainwater management model can realize the simulation of urban rainfall and runoff.In this paper,a rainwater pipe network model suitable for the study area is established by using SWMM rainstorm and flood simulation software,and the waterlogging situation in the study area is analyzed by introducing elastic analysis method.On this basis,a variety of waterlogging prevention and control measures are designed and optimized to solve the problems in the study area.Waterlogging has important reference value.The main research results are as follows:(1)The basic conditions of hydrometeorology,topography,geomorphology,geological soil and drainage pipe network in the study area are deeply analyzed.The regional SWMM model is established through the steps of generalization of drainage pipe network and division of sub-catchment area.Based on the empirical values of parameters,the main parameters of the model are calibrated with the proportion of pipes with different design standards in the study area as the calibration objective,and the rationality of the parameters is confirmed.The final parameters of the model are determined to provide model support for the follow-up simulation study.(2)The resilience analysis method is introduced to analyze the simulation results of waterlogging in the study area under the design rainfall conditions of 1a,2a,3a,5a,10 a,20a,50 a and 100 a.The results show that the drainage capacity of rainwater pipeline network in the year of drainage standard is still acceptable,and the overload and overflow of nodes and pipelines in the study area is serious in the year of waterlogging control standard.The elastic index of typical waterlogging nodes and systems is low and decreases with the increase of rainfall intensity,and the ability to resist rainstorm waterlogging is poor.Based on this,the causes of waterlogging in the study area are summarized and the key bottlenecks are pointed out.(3)Based on the analysis of hydrogeological conditions and construction conditions in the study area,the waterlogging prevention and control measures suitable for the study area are selected as concave green space,green roof,pervious pavement,rain bucket and ground rain water storage tank.The waterlogging prevention and control effects of the single measure are simulated by SWMM model.The results show that concave green space and green roof are suitable for runoff control in the study area.The control effect is better,and the effect of the underground rainwater storage tank on reducing the amount of water accumulated and improving the waterlogging elasticity index is better.On this basis,combined with the concept of joint application,the combined scheme design of various waterlogging control measures in the study area was carried out,and four combined schemes were designed and simulated.(4)Based on the theory of fuzzy decision-making,the evaluation system of fuzzy optimization index is constructed,including waterlogging elasticity index,runoff control index,economic cost index and social benefit index.The design scheme is optimized from runoff control angle,economic angle,ecological angle and comprehensive angle.Finally,the optimal scheme for runoff control is scheme four(concave green space,green roof,pervious pavement,rainwater barrel and underground rainwater storage tank).From the economic and comprehensive point of view,the optimal scheme is scheme three(concave green space,green roof,underground rainwater storage tank).From the ecological point of view,the optimal scheme is scheme two(concave green space and green roof).Resilience analysis of the optimal schemes is also carried out.