基于空间联系的城市腹地范围划分——以江苏省为例

Measuring Method of Urban Hinterland Based on Spatial Linkage:A Case of Jiangsu Province

以ArcGIS为平台,在1:25万基础地理数据、江苏省交通路网数据、江苏省各县(市)统计数据的支持下,应用"自下而上"的划分方法对江苏省1990年、1996年、2002年和2008年不同等级的城市及其腹地的吸引范围进行了划分。划分过程包括:运用因子分析得到65个城市的综合实力,利用可达性分析技术得到城市间两两时间距离,运用最大联系强度以及逐级归并方法确定不同等级城市及其腹地范围。结果表明:采用城市间两两可达性来代替直线距离,对划分结果的准确性有所提升;划分方法充分考虑了城市间的隶属关系,划分过程中充分体现了城市质量与城市间的时间距离,划分结果较好地体现了区域均衡。"自下而上"划分方法体现了与传统的"自上而下"划分方法完全不同的研究路径,作为城市腹地划分方法的一种补充,可供研究人员进一步理论和实证探讨。

With the development of computer technology and geographic information system （GIS）, three sig- nificant transformation appears in measuring method of urban hinterland. Firstly, the method develops from the qualitative to the quantitative. Secondly, GIS is increasingly integrated with traditional methods. Thirdly, time-distance gradually replaces physical distance, while they have the commom thinking to classify the cities by their qualities. The urban hinterlands can be deviede to different categories, which is called ＂top-down＂ method in this article. Since the method focuses on the quality without considering distance as a factor, the re- suits are not good enough in the area where the internal differentiation is significant. Therefore, the method named ＂bottom-up＂ is put forward here. And selecting Jiangsu Province as a case, the cities in it are divided to different levels and their hinterlands are measured in the years of 1990, 1996, 2002 and 2008 based on the 1： 250 000 basic geographic data, the transportation network data and the statistic data of counties （cities）. The di- vision process involves： to obtain the scales of 65 cities by factor analysis, to get the time-distance between cit- ies by the accessibility analysis, and to determine the levels of the urban and their hinterlands after merging them by grade through maximum spatial linkage. The result shows that： it is more accurate to use accessibility capacity than using the straight-line distance, since not only the comprehensive strength but also the location are taken into consideration in the former; the dividing result may fully reflect the regional balance since fully considering the relationship of subordination among those cities. On one hand, ＂bottom-up ＂method could re- fleet the regional balance well while ＂top-down＂ method would neglect it instead; on another hand, ＂bot- tom-up＂ method could not ensure central cities with high comprehensively capable are all divided as high level ones in the case that those central cities are of about the same strength and being close while ＂top-down＂ meth- od can make it. But as a completely different method from traditional ones, ＂bottom-up＂ method reflects a new study thinking which deserves researchers to make theoretical and empirical exploration further.