基于交通流的江苏省城市网络结构与空间 格局形变

地域差异导致城市间各种要素流动。随着信息技术的发展，时间和空间的邻近成本大幅缩减，地理空间形成基于城市关系重构的网络化地区。这些存在于网络中的相互作用可以称作“要素流”。“要素流”的存在，加速了信息时代城市和区域不同尺度下的空间重构。为了探究“流空间”下江苏省城市发展格局，通过参量替代法测度主要城市之间基于公路和高速铁路交通的联系强度，构建城市交通流网络，计算各网络节点的入度和出度，并划分网络层级。选取前5对、前10对、前20对以及首位联系强度网络，展开对江苏省主要城市交通流网络结构及城市格局的系统研究。在此基础上，考虑到江苏省的区位条件，引入外部中心城市影响因子，运用重心模型和多维尺度分析法，计算城市网络在受到外部中心城市影响后的重心偏移距离和方向，定量分析江苏省城市网络在二维空间中的格局形变。研究发现江苏省城市网络分异较为显著，自南向北形成典型的“核心-边缘”结构，在长江以南地区形成了斜“沙漏”状的城市集聚区，北部城市之间的联系强度偏弱，没有形成网络体系。受上海影响，江苏省城市网络发生了明显的重心偏移及空间集聚，且该种作用强度随空间距离的增加而逐渐衰退。

Analysis on spatial structure and pattern deformation of urban network in Jiangsu Province based on traffic flow

With the development of information technology,proximity,both in time and space is greatly reduced,and the networked region is formed by the geographic space based on the reconstruction of urban relations.Interactions within such a network are called the"element flow",which accelerate the spatial reconstruction of cities and regions at different scales in the information era.In order to explore urban development patterns of"flow space"in Jiangsu Province,urban competitiveness is evaluated using principal component analysis(PCA).The strength of the association between major cities based on highways and high-speed railways is measured using the parameter substitution method,and an urban traffic flow network is constructed.For each network node,the ingress and egress are calculated,and the network hierarchy is divided.The first 5 pairs,10 pairs,and 20 pairs of association strength networks and the first association strength network are selected to carry out a systematic study on the traffic flow network structure and urban pattern of major cities in Jiangsu.On this basis,considering that Jiangsu is an integral part of the Yangtze River Delta urban agglomeration,the provincial urban pattern is bound to the influence of other central cities in the urban agglomeration,thus underscoring external central cities as influence factors.By using the gravity center model and multidimensional scale analysis,the distance and direction of the center-of-gravity shift of the urban network after being influenced by external central cities are calculated,and the pattern deformation of the urban network in Jiangsu in two-dimensional space is quantitatively analyzed.It is found that Jiangsu has a remarkable urban network differentiation,with a typical core-edge structure from south to north,and an inclined hourglass-shaped urban agglomeration in the south of the Yangtze River,while a weak association exists between the northern cities,in addition to an absent network system.The urban pattern shows the status of overall fixedness and local rapid adjustment.Affected by Shanghai,significant center-of-gravity shifts and spatial agglomeration have happened to the urban network in Jiangsu,of which the intensity is inversely proportional to the spatial distance.However,for cities in the north of the Yangtze River in Jiangsu,Xuzhou plays a much stronger central role in the region than Shanghai.