| Urban agglomeration is an advanced form of regional economic development,and it is important to play the role of urban agglomeration as a “transportation engine”.The 2021 National Comprehensive Three-Dimensional Transportation Network Planning Outline states that “integrated transportation networks need to enhance interconnectivity and network resilience”.The urban agglomeration of the Guanzhong Plain has a good development foundation and great development potential,and has begun to form a multi-mode convergence mode on a large scale.However,from the current situation,the multi-mode transportation network is relatively sparse,and the coverage of high-speed rail transit is low,which cannot provide high-quality transportation options for travelers.In particular,railway networks,highway networks,aviation networks,etc,as open and complex systems,will face various disturbances during operation,such as extreme weather,major traffic accidents,man-made sabotage,etc,once such events occur,they will have a serious impact on the normal operation of the transportation network.Therefore,it is of great significance to evaluate the resilience performance of multi-modal transportation networks in different extreme scenarios and propose targeted resilience improvement strategies to ensure the smooth and efficient operation of the network.Based on the vector data of the highway network(expressway,national highway,provincial highway)and railway network(general railway,high-speed rail,intercity,bullet train,etc.)completed in the Guanzhong Plain urban agglomeration in 2021,this paper constructs a multi-mode transportation network topology model,calculates the topological parameters of the network based on complex network theory,and reveals the infrastructure and macro properties of the network.Secondly,the traffic nodes in the urban agglomeration of the Guanzhong Plain are classified,and the improved K-shell model is adopted to calculate the importance value of different nodes,which is committed to identifying the key nodes in the network.Thirdly,different extreme scenarios are constructed according to the idea of combination of extreme event factors + important channels,and the spatial location method and questionnaire survey method are used to determine the impact range of the attacked facility.On this basis,according to the definition and classification of multi-mode transportation network resilience in urban agglomerations,resilience attack strategies under different evaluation dimensions are proposed and corresponding algorithms are designed.Then,based on the characteristics of multi-modal transportation in urban agglomerations and the mechanism of“stimulus-reflection” of the network after external disturbance,the absorption,resistance and recoverability of the network structure were evaluated,and the network efficiency,average number of independent paths and Shannon entropy were selected as the quantitative indicators of network structural resilience,so as to construct a network structural resilience evaluation model.From the perspective of network passenger flow changing in time series,a network functional resilience evaluation model is constructed.Finally,the simulation of the network under different extreme scenarios and different attack strategies is realized through programming,and specific resilience improvement strategies and network optimization suggestions are proposed.Based on the resilience analysis framework of multimodal transportation network in urban agglomerations,this paper studies the resilience of multimodal transportation networks in urban agglomerations in the Guanzhong Plain under different extreme scenarios,which helps to identify the weaknesses of different channels in the network,thereby reducing the degree and area of network “paralysis”,ensuring network smoothness to the greatest extent,and providing certain support for improving the travel quality of travelers and improving the efficiency of system operation. |
PDF Full Text Request