武汉都市圈经济联系的空间结构

The spatial structure of economic linkage of Wuhan metropolitan area

都市圈空间结构是城市体系中最综合、最富于变化的热点部分。基于武汉都市圈近年来的统计资料,构建经济联系强度模型,定量分析武汉都市圈空间竞争与范围的动态性特征:中心城市对外经济联系存在主要方向,具有时间惯性,空间极化明显;地域空间上经济联系作用强度距离衰减,形成圈层结构分异。从点、线、面组合关系角度,构建节点中心性、通道网络性、范围系统性指标,定量揭示出武汉都市圈经济联系的空间结构等级层次性特征:中心城市中心性等级差异明显,空间分布不均,与交通地理区位紧密相关;主要通道与侍服能力也存在等级层次性,明显形成两城际交通走廊;中心城市腹地范围与自身外向经济联系强度密切相关,受自然地理、行政区划影响明显。

The spatial structure of metropolitan area is the most integrated and most diverse part of urban system. It is composed by different ranks of spatial elements such as cities （nodes）, spatial flows （functional linkages）, channels （linkage axis） and action fields （the attraction range of each city） and so on. The spatial structure of metropolitan area is represented as the spatial combination relationship of three factors including point （city and urban system）, line （economic linkage channels） and surface （urban hinterland）. Based on the statistical data of Wuhan metropolitan area in recent years, using SPSS mathematical statistical technique and GIS spatial analysis function, we build an economic linkage intensity model and investigate the dynamic characteristics of the spatial competition and its range of Wuhan metropolitan area. It is found out that： （1） there are some main linkage directions in the external economic linkage of central cities, and its temporal inertia and spatial polarization are also very obvious; （2） the external economic linkage intensity of central cities is distance decay, which leads to a regional layered spatial structure. Then from the aspects of point, line and surface, we build and compute some useful indices which are the centralities of economic linkage node （central city）, the network connectivity of economic linkage channels （transportation network） and the regional organization of economic linkage range （urban hinterland）. With the aid of these indices, we can quantifiably analyze and point out the hierarchical characteristics of the economic linkage spatial structure of Wuhan metropolitan area. It is concluded that： （1） the centrality hierarchy of central city is quite different, their spatial distribution is uneven and has close relationship with transportation location; （2） the development and service function of linkage channel is hierarchical, and two inter-city transportation channels have been formed significantly; and （3） the influence range of economic linkage is closely related to external economic linkage intensity of central cities, and it is also greatly affected by its regional natural condition and administrative regionalization.