武汉都市圈城际联系通达性的测度与分析

Accessibility Analysis on the Spatial Linkage of Wuhan Metropolitan Area

空间-距离-通达性已经成为城市区域一体化联系与发展的先决条件。当前都市圈城际联系发展与交通网络建设存在明显的不同步现象,矛盾解决的关键是优化其路网通达性空间格局。以武汉都市圈为实证对象,构建最短距离矩阵,引入时间、空间通达性模型,建立高等级路网发育评价指标体系,从节点体系与网络体系两个角度,定量分析武汉都市圈城际通达性变化及其空间格局,揭示出:圈域城镇(节点)体系通达性空间差异明显,与城市自身交通区位、经济发展水平密切相关,其空间格局与城镇等级规模呈共轭协同关系,不同空间等级节点形成以武汉为中心的同心圈层与"轴—辐"网络空间格局;快速交通干道网络(高速公路、铁路等)是城市通达性空间演变的重要推动力,使其空间收敛减速,形成显著的带状分异格局,初步形成沪蓉东西向、京珠南北向的两大城市经济联系交通走廊;圈域城际交通干网发育程度偏低,处于回路网络水平,高等级路网扩展潜力巨大。

Space-distance,accessibility has become a precondition for the linkage and development of urban regional integration. Currently, the spatial linkage development of metropolitan area and the traffic network construction are obviously asynchronous. The key to solving the contradiction between them is that we should optimize the spatial structure of road network accessibility. In this paper, taking Wuhan city as a case, we construct shortest-distance matrix, introduce temporal and spatial accessibility models, build the evaluation index system of the traffic network with higher hierarchy development, and quantitatively investigate the changes and spatial structure of the urban accessibility of Wuhan metropolitan area. It is found out that： （1） circular city accessibility is quite different in space. This accessibility is closely related with urban traffic location and the city＇s economic development level, and the relationship between its spatial structure and urban hierarchy-size is conjugated and synergic. Moreover, different spatial-level nodes form a homocentric layer with Wuhan as its center and demonstrate a ＂node-spoke＂ network structure; （2） fast traffic networks （highways, railways etc.） are important impetus to the evolution of urban spatial accessibility; （3） it leads to deceleration of its spatial convergence and forms a significant branded fractionation. Two traffic corridors for urban spatial linkage are formed primarily, which are east-west of Shanghai-Chongqing railway and southnorth of Beijing-Guangzhou railway; and （4） the evolution degree of circular-city traffic network is a little slow as it is in the condition of loop network and the extending potential for traffic network of higher hierarchy is quite great.