徐州城市形态演变的分形分析

基于城市扩展图和多时相Landsat遥感影像资料，应用分形理论，对1949年以来徐州城市形态的演变进行定量分析，揭示了徐州城市形态在不同时期的扩展特征。结果表明：徐州城市形态具有分形性质，城市形态的演变是多种因素综合作用的结果，尤其与经济发展的周期性变化密切相关。城市形态的演变经历了迅速扩展期、缓慢扩展期、恢复扩张期、快速推进期和稳步扩张期。在空间上，徐州城市形态一直处于外部扩展一轴间填充一外部扩展的循环过程中。在扩展方向上，1987年以前，城市的扩展重心向东北方向转移；1987年以后，扩展重心转向东南方向。

THE FRACTAL ANALYSIS ON URBAN FORM EVOLUTION OF XUZHOU

Basing on the city expansion maps from 1949 to 1960, and a series of remote sensing images from 1979 to 2003 of Xuzhou City, using fractal theory, quantitative analysis had been conducted to research the urban form evolution since 1949, revealing the urban form expansion process and the character in the different time.Result indicates that the Xuzhou urban form bears clear fractal characteristics.Urban form evolution is that the various factors synthesize the effect result, and the urban form evolution closes correlation with the economical periodic variation especially.The urban form evolution experienced quicker extension period, slower extension period, restored expansion period, fast advancement period and extension with stable period.In the process of the circulation that the Xuzhou City form expands on space, always in filling up the outside among extendedaxis of outside.On being expanding direction, before 1987, the urban expansion barycenter shifts toward northeast direction; after 1987, the barycenter changes to southeast direction.