Multi-modal Transportation Network Modeling And Integrated Resilience Measurement In Metropolitan Areas

A metropolitan area is a spatial pattern of urbanization that emerges from the close interaction between a large city and its neighboring cities and counties after it has reached a certain stage of development.At present,the development of China’s metropolitan areas is still at a preliminary stage,and the cultivation and development of modern metropolitan areas requires,first of all,the promotion of the construction of an integrated,multi-level transportation network system.The Outline for the Construction of a Strong Transportation Country and the Outline for the Planning of a National Integrated Three-dimensional Transportation Network also clearly point out the need to promote the integrated development of transport in metropolitan areas and build a resilient integrated three-dimensional transportation network,so how to promote the construction of an efficient and stable modern integrated transportation network is an issue that needs to be focused on.It is important to evaluate the comprehensive resilience of transport networks in the face of external disturbances through a multi-dimensional and integrated perspective,and to explore the paths that can effectively improve the comprehensive resilience of multi-modal transport networks in metropolitan areas in different dimensions,in order to promote the construction of efficient and stable multi-modal transport networks in metropolitan areas.This paper took metropolitan area multi-modal transport networks as the research object,established the construction process of different types of transport networks based on the complex network approach,then set the load and capacity levels of nodes in metropolitan area multi-modal transport networks based on the load-capacity model,and defined the load redistribution model in the operation of metropolitan area multi-modal transport networks.Then the network resilience evaluation indexes of different dimensions were constructed from three levels:network as a whole,network structure and network function,and the integrated resilience indexes of the metropolitan area multi-modal transport network were constructed based on the integration perspective.Finally,a simulation analysis of the integrated resilience of multi-modal transport networks in the Xi’an metropolitan area was carried out,and the sensitivity levels of different modal transport sub-networks in the metropolitan area multi-modal transport network were analyzed through scenario simulation methods.The simulations were carried out to compare the effects of the implementation of strategies to improve the resilience level of integrated multi-modal transport networks in different metropolitan areas.The study mainly draws the following conclusions:（1）In the metropolitan area multi-modal transport network,the sensitivity of each modal transport sub-network is ranked from highest to lowest:V intercity high speed railway>V high-speed railway>V ordinary railway>V intercity _{passenger transport},and different modal transport sub-networks play different roles in the metropolitan area multi-modal transport network.（2）When the metropolitan area multi-modal transport network is under attack,it is necessary to focus on the change in the percentage of network node failure before 60%and take timely measures to reduce the percentage of failed nodes.（3）The node capacity level of the metropolitan area multi-modal transport network needs to be dynamically adjusted,with theβlevel appropriately set at 0.2 in the daily operation of the network and adjusted to 0.7 in the face of extreme weather or during holidays.（4）In the operation of the metropolitan area multi-modal transport network,the process of shifting the passenger flow load of the network nodes focuses on the transport efficiency factor to enable the metropolitan area multi-modal transport network to have a more comprehensive network resilience level.（5）The recovery strategy based on the node load capacity level has the best effect on improving the integrated resilience level of the network recovery process,and the dynamic recovery process of the network while cascading failures occur in the network can comprehensively improve the resistance to attacks and the network recovery ability in different dimensions of the network.