县域城乡聚落规模体系的演化特征及驱动机理——以江苏省张家港市为例

Evolution characteristics and driving mechanism of urban-rural scale system at county level:A case of Zhangjiagang city, Jiangsu province

从城乡聚落规模的大小、结构、分布三个基本属性出发,以经济发达的江苏省张家港市为案例地,以土地利用数据和遥感影像为数据源,揭示了1995-2015年间县域城乡聚落规模体系的演化特征及驱动机理。结果表明:(1)县域城乡聚落数量显著减少、用地规模显著增加。(2)城—镇—村规模结构从"凸字型"经"金字塔型"向"橄榄型"方向演化;不同阶段、不同规模等级的城乡聚落的成长速率不同;城乡聚落的齐夫指数偏大但增长放缓,规模结构总体上符合位序—规模法则。(3)城乡聚落规模分布的不均衡程度不断增强,但极化发展速率逐渐减小;空间集群分布特征显著,聚类中心分布趋于均衡化;城乡聚落用地的时空变化存在显著的地域差异,以城镇用地变化为主。(4)驱动机理是由地理环境、区域经济、交通网络、制度与管理四个主要因素共同作用构成的"四轮"驱动过程。

In the context of the new era,it is of great theoretical and practical significance to promote urban-rural integrated development and rural vitalization by means of studying the urban-rural scale system.The concept of urban-rural scale system had three essential characteristics of size,structure and distribution,therefore the three-dimensional analytical method had been established.This paper explored the evolution characteristics and driving mechanism of urban-rural scale system,based on both the land change survey data and remote sensing data in 1995,2005 and 2015,using the well-developed Zhangjiagang city of Jiangsu province as a case.Several conclusions can be drawn as follows:(1)The number of urban-rural settlements was continually decreasing,but the scale of built-up areas showed the opposite trend during 1995-2015.(2)The type of city-town-village scale structure changed from'stelepattern'to'pyramid-pattern',then to'olive-pattern'from 1995 to 2015.The number and builtup area of high grade settlements were increasing,and those of low grade settlements were decreasing.There was close correlation between the growth speed of settlements and their sizeclasses.Zipf’s index of settlements size was generally high,with the decreasing growth rate of it,and the outcomes of model fitting conformed to the law of rank-size as a whole.(3)The spatial differentiation of urban-rural scale system had become increasingly obvious during the study period.However,the speed of polarization had decreased in the 10 years.There existed significant characteristics of spatial agglomeration of settlements,and distribution of cluster centers developed toward the direction of equalization.The spatial and temporal changes of urban-rural construction land were remarkably different in different regions,but the land-use change was mainly found in the urban areas.(4)This paper constructed a'four-wheel'driving mechanism of urban-rural scale system,including four driving factors.More specifically,geographic location was the fundamental factor limiting the development of urban-rural scale system;regional economy was the internal motivity impelling the settlements to evolve toward an advanced one;transport network was a kind of important catalyst in the process;institution and administration had become the indispensably external driving forces.These four factors,just like the four wheels of a car,interacted each other and together impelled the evolution of urban-rural scale system.