环渤海城镇建成区时空动态特征分析

以环渤海三省两市为研究区,基于20世纪70年代末期以来5个时相的Landsat MSS/TM/ETM+遥感影像提取县级及以上城镇建成区的空间分布图形信息,采用扩展动态度、扩展强度和空间自相关指数等指标分析环渤海区域城镇扩展的时空动态特征.结果表明:(1)20世纪70年代末期以来,环渤海区域城镇用地不断扩展,各阶段扩展速度和扩展强度呈上升趋势,而扩展动态度趋于减少.(2)不同类型城镇扩展的总体趋势基本一致,但类型间差异亦较显著.(3)城镇扩展动态度的总体空间格局呈显著正相关,高值区空间分布的阶段性特征显著,且呈现沿交通干线分布和变化的特征.(4)城镇扩展强度总体上趋于随机分布,但局部地区呈集聚分布态势,高值区多较为孤立地分布在大城市或其周围地区,并表现出据点式的演化趋势.

Dynamics of Urban Expansion in Circum-Bohai Sea Region

China has experienced rapid urban expansion since reform and opening-up.In this paper,the Circum-Bohai region(CBR) is selected as the study area.Based on five years of Landsat MSS/TM/ETM+ images which were mainly acquired in 1970s,1990,2000,2005 and 2010 respectively,the spatial boundaries of all the cities and towns have been interpreted by GIS techniques.Furthermore,the dynamic characteristics of urban expansion in the CBR were analyzed quantitatively by some indices.The results are drawn as follows:(1) In the past four periods,the average annual growth area and growth intensity of urban expansion of the whole CBR were accelerating,while the dynamic degree was decreasing.Cities in different administrative hierarchy positions followed the same trend.(2) The highest growth intensity was always mega-cities,provincial cities,county-level cities and lowest counties.However,cities with the largest annual growth area or dynamic degree changed with time.(3) In the perspective of the dynamic degree of urban expansion,high-high value clusters tended to distribute along the important transportation axes and transferred evidently in different periods.(4) As for the growth intensity,high-high value clusters always distributed around big cities and expanded based on the previous.