Simulation Of Rainstorm Waterlogging In Zhenjiang City Based On PCSWMM

With the rapid development of global climate warming and urbanization,atmospheric precipitation increases and surface runoff increases.The urban drainage system cannot cope with sudden rainstorm,and a large amount of rainwater cannot be discharged in time,resulting in the phenomenon of waterlogging in urban areas.Urban waterlogging leads to road traffic paralysis,inconveniences for residents to travel,and even casualties when it is serious.Therefore,the study of urban waterlogging has become a hot issue in society.In this paper,the core area of Zhenjiang main city is taken as the research area,considering the natural geographical situation and the current situation of drainage pipe network in the research area,Chicago rain pattern is taken as the design rain pattern,and four kinds of return period rainfall of 2a,10 a,25a and 50 A are considered as the rain gauge data input model.The study area was divided into drainage zones,the data modification and generalization of pipe network,and the parameters extraction and calibration were completed to construct the one-dimensional pipe network model.The evaluation of the drainage capacity of one-dimensional pipe network shows that the overall design standard of pipe network in the study area is low,and it cannot meet the drainage design capacity of 10 a and above recurrence period.PCSWMM two-dimensional modeling module was used to construct the two-dimensional surface model of the research area,and the rainstorm water accumulation situation under the recurrence period of 10 a,25a and 50 a was simulated.The results showed that the main urban area of zhenjiang was flooded at different depths due to the relatively small green area,large proportion of hard roads,low-lying terrain and insufficient drainage capacity of pipe network.The overall risk of waterlogging in the 10-year return period is relatively light,which does not affect people's daily life.The risk of waterlogging in the 25-year return period is relatively high,which has a great impact on people's lives.The higher risk of waterlogging in the 50-year return period is deepened,and the time and area of waterlogging increase,which will lead to traffic paralysis and seriously affect the travel of residents.The simulation results of waterlogging are verified with the data,and the results show that the simulation results are more in line with the actual situation,which can provide a theoretical basis for the relevant departments to understand the waterlogging points in zhenjiang and to specify waterlogging prevention schemes.41figures,11 tables and 78 references are included in this dissertation.