Simulation On The Impact Of Storm Flood On Urban Road Network

Urban floods caused by heavy rains have varying degrees of impact on a global scale,especially in recent years,with abnormal climate change and accelerated urbanization,leading to frequent occurrences of flooding or flooding in extreme cities.As an important link connecting various subsystems,urban roads are the urban arterial system.With the continuous increase of car ownership,traffic congestion and traffic accidents frequently occur.Especially in recent years,the impact of urban torrential rains on the transportation system is particularly serious,causing subsequent management problems in many cities,such as traffic congestion and loss of property.In order to scientifically deal with the problem of urban floods and the traffic disruption or congestion under the influence of the storms,reveal the response characteristics of traffic behaviors in the torrential rain,identify the easy-to-water sections and the congested sections in the storms,and estimate the occurrence of heavy rains.Travel costs.Research on the impact of floods caused by guilt and road flooding on the operation of urban road transport systems and urban residents’ travel activities is particularly important.The research on the impact of storm flood on urban road network is divided into two aspects:one is the numerical simulation of urban storm flood and the other is the simulation study of urban road network traffic flow distribution.The former provides road flood information,the latter provides road network traffic distribution,and the two aspects of research combine the established road network travel time model to compare the travel time of the road network under different return periods to prevent disasters.The disaster reduction department and the traffic management department shall provide scientific reference for formulating corresponding control strategies.At present,the research on urban road network under the influence of storm and flood at home and abroad mainly focuses on the research of highway,expressway or part of the road,and focuses on the study of traffic flow characteristics such as traffic flow,density and speed;for macroscopic concept There is less research on the impact of the entire road network,and no specific indicators are used to assess the magnitude of the impact.In view of the above problems,this paper studies the simulation of the impact of storm floods on urban road networks from the following aspects:(1)Numerical simulation of urban storm floods.This paper analyzes the processes of production,sinking,drainage and water accumulation in urban complex environment,and compares the existing urban flood simulation software,and selects SWMM software with broad application advantages to establish a dual drainage system suitable for the study area.model.The Horton model is used for surface runoff,and the nonlinear reservoir method is used for surface convergence.In order to obtain a more accurate solution,the flood evolution uses dynamic wave method.Apply to the specific case of Jinan City Research Area to verify the feasibility of the road-pipe network dual drainage model.(2)Simulation of urban road network traffic flow distribution.In this paper,the OD matrix of the study area is reversed by the OD backstepping method through the traffic investigation of the road section,and then the reversed OD matrix is distributed to the road network through the traffic distribution method to obtain the specific traffic of each section.The physical model of the road network in the study area was established by TransCAD,and the traffic volume was investigated by using the road section and the gravity model was used to reverse the OD matrix of the study area.Based on the inverse OD matrix and user balance method for segmental traffic distribution,the traffic flow distribution of the network segment is obtained.The urban road network traffic flow distribution model is applied to the example to verify the feasibility of the road network traffic flow distribution model.(3)Simulation of the impact of storm floods on urban road networks.The roads caused by road flooding or guilt in heavy rains are not smooth or even interrupted,resulting in an extension of the passage time of the entire road network.The road flood elements simulated by the road-pipe network dual drainage system model are combined with the road flood safety standard to determine whether the flood road section can pass.By simulating the traffic distribution of road network traffic under normal weather and heavy rain,combined with the travel time of each road segment,the road network travel time model is established.The travel time and delay time of the road network under different rainfall conditions in the study area are summarized,and the impact of heavy rain in different return periods on the urban road network is evaluated.The research results provide a scientific reference for the disaster prevention and mitigation departments and traffic management departments to formulate corresponding control strategies.