| Urban public transportation system is a lifeline project for the stable operation of urban space.In recent years,traffic disruptions such as traffic congestion,road blockages,and sudden accidents caused by multiple extreme meteorological disasters have seriously affected the stable operation of the urban public transportation system.The resilience is an important performance indicator to measure the anti-interference and recovery ability of urban public transportation systems under disasters.Therefore,studying the resilience of urban public transportation systems under extreme meteorological disasters,and systematically analyzing the key nodes and resilience improvement strategies of urban public transportation systems under extreme meteorological disasters are of great significance for ensuring the safe operation of urban public transportation systems and disaster prevention and mitigation.Taking typhoon and rainstorm as examples,this paper systematically analyzes the resilience of urban public transport system under extreme meteorological disasters.Firstly,based on the theory of regional disaster system,the impact mechanism of typhoon and rainstorm on urban public transport system is analyzed,and the impact of typhoon and rainstorm on urban public transport system is quantified by risk index;Secondly,using the Space L model,the bus subway subsystems are abstracted into a bus-subway urban transportation network(Bus-Subway Urban Transportation Network,B-S UTN),and a cascading failure model for B-S UTN based on a nonlinear load-capacity model is proposed to analyze the impact of extreme meteorological disasters on the cascading failure of urban public transportation systems;Then,using resilience indicators to measure the performance of urban public transportation systems under extreme meteorological disasters,a resilience evaluation model of B-S UTN based on system performance curves is proposed.Meanwhile,the largest connectivity subgraph ratio and transportation service efficiency,are selected from the structural and functional dimensions to quantify the resilience of B-S UTN;Finally,taking the bus and subway systems in the central region of Shanghai as an example,the resilience of B-S UTN in the central region of Shanghai under extreme meteorological disasters is simulated,which is caused by typhoon rainstorm;meanwhile,the key nodes in the Shanghai’s B-S UTN and resilience improvement strategies are also analyzed.The research results show that:(1)The extreme meteorological disaster of typhoon and rainstorm will cause great damage to the resilience of B-S UTN,and the cascading failure caused by passenger flow overload will cause secondary damage to the connectivity and efficiency of B-S UTN;(2)The B-S UTN in the central region of Shanghai is a large-scale network with relatively low transport efficiency,which is between the random network and the scale-free network;(3)When α= 0.15 and β= 0.34,the B-S UTN in the central region of Shanghai will have better resilience performance;(4)The structural resilience of B-S UTN in the central region of Shanghai is better under the degree priority recovery strategy,and the functional resilience is better under the passenger flow priority strategy.The network needs to be targeted for recovery.The recovery strategy and method can be selected according to the purpose of structural resilience and functional resilience;(5)High risk index nodes,cascading failure critical nodes,high degree value nodes,and high passenger flow nodes in the B-S UTN are important for improving the network resilience;(6)Increasing the capacity nodes,using recovery strategy and protecting key nodes all can effectively improve the resilience of B-S UTN in the central region of Shanghai.This paper studies the resilience of urban public transport systems under extreme meteorological disasters,providing a decision-making basis for emergency management and control strategies of urban public transport management departments under extreme meteorological disasters. |
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