城市轨道交通线网形态和客流分布的分形特征分析

Fractal Characteristics Analysis of Urban Rail Transit Line Network Morphology and Passenger Flow Distribution

为研究城市轨道交通线网形态和客流的时空分布变化特征问题,结合分形理论和客流分配理论,提出了城市轨道交通线网和客流特征的分形计量方法。提出了4个半径维数和2个分枝维数指标,分别对城市轨道交通线网和客流的复杂程度及其变化特征进行数字描述。基于ArcGIS软件平台,以北京地铁为例,验证了方法的合理性与有效性。实例测算分析结果表明:北京五环内区域的地铁线网结构和客流分布均存在分形特征;线网供给和乘客需求基本匹配,但局部区间和换乘车站超载严重,线网仍需加密。

To study the spatial and temporal distribution characteristics of urban rail transit line network morphology and passenger flow,a fractal measurement method of urban rail transit network and passenger flow characteristics is established based on fractal theory and passenger flow distribution theory.Four radius dimensions and two branching dimensions are proposed to describe the complexity and variation characteristics of urban rail transit network and passenger flow.Taking Beijing Metro as an example,the rationality and validity of the method are verified on ArcGIS platform.The calculation and analysis show that both the metro network structure and passenger flow distribution within the Fifth Ring Area of Beijing have fractal characteristics,and the network supply primarily matches the demand of passengers.However,the overload of certain intervals and transfer stations is critical,meaning that the network requires densification.