The Evolution Analysis Of Urban Rail Transit System:Network Structure And Passenger Flow

Urban rail transit has been in the period of network operation.The scale of the urban rail transit network expands rapidly,and the topological structure of network becomes more complex.These factors will affect the spatial distribution of passenger flow to a certain extent.Accordingly,the change of passenger flow characteristics brings new problems to the network planning and operation.Therefore,it is necessary to explore the evolution of urban rail transit,which including topological network and weighted network,so as to provide theoretical guidance for the planning and development of urban rail transit.The main research contents are as follows:Adopting the complex network theory,this paper constructed a topological network model of urban rail transit with section distance The method of identifying the critical nodes was proposed by integrating the characteristic index and node importance contribution matrix.In this paper,the evolution of topological network was analyzed from the aspects of the network morphology,the development index and the critical nodes.Taking Chengdu Metro as an example,the results show that,the form of its network has evolved into an annular radial network,and the network development is relatively mature.Most of the critical nodes are transfer stations.As the network expanded outward,the stations on the loop line become the critical nodesA weighted network model with section passenger flow was constructed.By analyzing the correlation between weighted network and topological network,this paper analyzed the evolution of weighted network from the change of passenger flow and characteristic index.The results of Quadratic Assignment Procedure show that,there is a significant relationship between weighted network and topological network,and the formation of weighted network is affected by topological network.The change of passenger flow before and after the change of network structure is analyzed,and the characteristic indexes are compared.With the evolution of network,the number of travel routes available to passengers increases,resulting in the change of passenger flow distribution.A Coupled Map Lattices model of the topological network and the weighted network was constructed to analyze the stability of urban rail transit network.The indexes were proposed to analyze the stability of network,and the influence of topological structure evolution on network stability was discussed,as well as the effects of node importance and the different disturbance values on the stability of the network.The results show that,the stability of the network improves with the evolution of the network.The greater the interference intensity to the critical nodes,the higher the node failure,the faster the network breakdown.It shows that the protection measures of critical nodes play an important role in improving the operation and management of urban rail transit network security.