近30年来苏锡常城市增长形态过程与聚散规律

基于苏锡常地区多时相遥感数据,采用缓冲区分析方法和象限分位分析方法,并结合景观格局指数,定量比较苏州、无锡、常州城市建设用地近30 a来扩展过程,研究城市空间分散-集中的规律性,揭示城市增长空间模式特征。结果表明:1979～2006年间苏锡常城镇用地面积扩展巨大,3市扩展强度指数随圈层半径变化轨迹高度一致,扩展强度峰值约10 a向外推移2 km;苏锡常城镇扩展形态均呈分散-集中交替变化,但研究中未观测到完整周期;城市外部轮廊变化差异明显,以开发区为代表的政府干预行为主导城市扩展方向。苏州城市用地扩展主要集中在东片工业园区和南部城区,无锡城市用地各向扩展相对均衡,常州城市用地扩展主要集中在北部高新技术产业区及城东工业区。

Diffusion and Aggregate Process of Urban Pattern in Suzhou,Wuxi and Changzhou cities over the Recent 30 Years

The authors performed a quantitative study on characteristics of urban expansion in the Suzhou,Wuxi and Changzhou cities(SWC) by means of quadrant analysis and buffer analysis with Landsat MSS/TM/ETM images acquired in 1979,1991,2001and 2006.The results indicated that the spatial pattern of urban growth behaved certain regularity in the last 30 years.Expansion intensity index of the three cities showed a highly coherence with circle radius,and the peak of expansion intensity moved gradually from the inside out with time.Combined with experimental analysis for major growth axis,it is suggested that SWC region might present incomplete filling and axial development.The expansion pattern exhibited an alternating process that the complete cycle of diffusion-aggregate-diffusion was not observed in the whole city in 1976-2006.It was also found that urban expansion intensity index was quite different in different directions at different time.Various development zones which were initiated and located by the government played an important role in driving new urban growth.In Suzhou city,the eastern industrial park and southern districts lead the whole expansion process.In Wuxi,the expansion of all directions was relatively balanced.owing to the private economy development.In contrast,the urban expansion of Changzhou showed a multi-polarization trend which flocked to northern high-tech industrial zones and eastern industrial zones.A number of alternating development axes emerged as a result of the top-to-bottom control on urban development in the city.