Research On Urban Road Network Resilience Under The Influence Of Waterlogging Disaster

In recent years,due to the abnormal global climate change and the lag in the construction of urban drainage and waterlogging prevention facilities,many cities in my country have frequent waterlogging disasters,which often lead to malfunction of road networks and damage or even loss of transportation system operations.Some scholars at home and abroad found that different road networks have different anti-interference capabilities against waterlogging disasters,so they proposed the concept of road network resilience to describe the road network’s disaster resistance capabilities,and studied its influencing factors and qualitative and quantitative methods.Accurately grasping the internal mechanism of road network resilience is crucial to improving the ability of urban road network disaster prevention and mitigation.The current road network resilience research is still in its infancy.The existing evaluation indicators often describe road network resilience from a certain aspect.There are even fewer studies on the resilience of road networks under flooding disturbance.Therefore,how to reasonably evaluate the resilience of the urban road network under waterlogging conditions needs to be solved urgently.Because of this background,to comprehensively evaluate the resilience of urban road networks under the influence of waterlogging disasters,this paper researches the following aspects.First of all,obtaining road water depth data is the basis for researching the resilience of urban road networks.Because of the shortcomings of traditional survey methods,this paper designs and develops an ultrasonic water depth measurement device based on the STM32 microcontroller.The hardware and software parts of the device were designed respectively,and many experiments were performed in different measurement environments to modify the algorithm model.The experimental results show that the accuracy of the device meets the research requirements,it can realize the non-contact measurement of the road water accumulation depth,and can quickly and accurately obtain the spatial distribution of road water accumulation sites and water accumulation depth data.Secondly,due to the impact of waterlogging sites,road network traffic will actively or passively detour.Therefore,based on the acquisition of road water depth data,the study of traffic flow redistribution under the influence of waterlogging disasters is carried out.The original method is used to construct the road traffic network model of the study area,divide the traffic districts,and reverse the current OD matrix.According to the road water depth data collected by the water depth measuring device,the road traffic parameters under the influence of different waterlogging sites are reduced and corrected,and the traffic impedance under the influence of different waterlogging sites is calculated.The user balanced traffic distribution model is used in Trans CAD software to complete the traffic flow redistribution of the current OD travel matrix after the road network is degraded.Thirdly,the definition of urban road network resilience is proposed,the influencing factors of urban road network resilience are determined,and a two-level evaluation index system for urban road network resilience is constructed based on the complex network theory.The entropy method is used to determine the weight value of the second-level evaluation index of the road network resilience index,and the coefficient of variation method is used to determine the weight value of the first-level evaluation index of the road network resilience index.Using road network resilience index,accumulation time of stagnant water,and dissipation time of stagnant water as evaluation indicators,a road network resilience triangle evaluation model is established,and the CCR model of data envelopment analysis method is used to solve it.This model can be used to compare different levels of waterlogging disasters road network resilience under the influence.Finally,taking the road network in Cangshan District,Fuzhou City as an example,the road network resilience evaluation model in this paper is used to evaluate the road network resilience under the influence of various water accumulation sites in the study area,and to identify the road water accumulation sites that most damage the road network resilience.Propose corresponding improvement measures for each stagnant site,evaluate the degree of improvement of the road network flexibility by each improvement measure,and determine the optimal improvement plan for each stagnant site,to improve the flood-prone areas,traffic management,and road network prevention provide a reference for disaster mitigation.The road network resilience evaluation model established in this paper can be used to evaluate the resilience of urban road networks under the influence of waterlogging disasters,to explore the resilient characteristics of urban road networks to waterlogging disasters,to reduce the damage of waterlogging disasters to urban road networks,and to ensure that the urban road network is in a sudden It can still operate more efficiently in the event of waterlogging disasters,which has certain application value.