Accessibility Analysis on the Spatial Linkage of Wuhan Metropolitan Area

Space-distance-accessibility has become a precondition for the linkage and develop-ment 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 south-north 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.