Spatial Pattern And Network Of Inter-urban Passenger Transport Connectivity In The Yangtze River Economic Zone

Most recently,research on spatial complexity of integrated transportation has become a hot spot and difficulty in transportation geography.Rapid development in transportation is observed in the Yangtze River Economic Zone(hereafter YREZ)which results in emergence of integrated transportation network made up with transportation modes such as railways,highways,airlines and inland navigations,etc.,while the regional differentiation and spatial organization rules behind it need to be excavated.It is of great theoretical and practical significance to depict the spatial pattern of inter-urban passenger transportation under different means of transportation in the YREZ for perfecting the theoretical system of transport geography complexity and promoting the integration of transportation in the YREZ.Therefore,this paper builds the weighted passenger connectivity and network model based on data mining of inter-urban passenger railway,highway,and airline shifts.From the two dimensions of connectivity and network and the perspectives of comparative and comprehensive analysis,a full description of the spatial pattern of inter-urban passenger transport connectivity and network in the YREZ is carried out.On the one hand,spatial similarity and diversity of inter-urban passenger transport connectivity and network under different transportation modes are portrayed in terms of spatial distribution and agglomeration.On the other hand,it introduces travel time to construct a weighted comprehensive network model and reveals the spatial heterogeneity of the inter-urban integrated passenger transport network from the perspectives of nodal centrality,urban-pair connectivity and subnetwork community.The results are indicated as follows:On the one hand,the intensities of railway,highway and air passenger transportation all exhibit typical spatial heterogeneity: high unevenness and agglomeration.The intensities of the three modes of transportation is highly concentrated in a few capital cities and the developed areas of the lower reaches of the Yangtze River,showing significant administrative and economic orientation.In addition,the inter-urban passenger transport intensities under the three modes of transportation are also significantly different.Firstly,the degree of spatial disparity varies,presenting the sequence of airlines>railways>highways.Secondly,there are differences in spatial forms.The intensities of passenger transport links show an imbalance between the east and the west and north and south ends.The distribution of high-value areas is a combination of spot-like inlays and strip extensions.The points are concentrated in railway hubs such as Wuhan,Guiyang,and Chengdu.Cities,and strip areas along the Shanghai-Nanjing and Shanghai-Kunming Railways.The community effect of highway passenger transport intensity is obvious,forming the Yangtze River Delta Urban Agglomeration with Shanghai as the center and Chengyu Urban Agglomeration regarded Chengdu as the hub.The spatial distribution of air passenger transport intensity is mainly punctiform mosaics and is highly concentrated in capital cities such as Shanghai,Chongqing,Chengdu and Kunming.The integrated transport passenger transport intensity shows three pillars(Shanghai,Nanjing,and Hangzhou)and simultaneously three districts(the central and southern Yangtze River Delta Urban Agglomeration,the Poyang Lake Urban Agglomeration,and the Changsha-Zhuzhou-Xiangtan Urban Agglomeration)framework.The integrated passenger transport intensity in the northern middle reaches and upper reaches of the Yangtze River is significantly lower.On the other hand,railway,highway,airline and integrated passenger transport networks have significant structural complexity.From the perspective of topological statistics,the four types of transport networks have developed into small world networks to different extents.Ground transportation networks,including railway,highway,and integrated passenger transport networks are more randomly connected,while airline networks have scale-free features.From the perspective of spatial distribution,the Yangtze River Delta and the Triangle of Central China and their internal passenger connections constitute the mainstay of the railway network;the strong link of the highway passenger transport network is mainly concentrated between the southeastern coastal cities and major cities in Jiangsu,Zhejiang and Shanghai,and within Chengyu Urban Agglomeration;the main airline passenger connections are concentrated within Yunnan Province,and between Shanghai and the western aviation hub(Kunming,Chongqing,Chengdu).From the perspective of community organizations,the integrated passenger transport network is significantly affected by administrative border and geographical proximity,and can be divided into eight regional sub-networks,including seven single-core communities and one dual-core community.The intensity of passenger transport links between communities follows the law of geographical distance attenuation,making cities tending to connect with neighbors and gather in groups.The nodes in communities present typical vertical-level links,and the transportation hub cities are in a dominant position because of hierarchical organization.