1989~2015年武汉市城市格局时空演变分析

城市格局时空演变以土地利用变化为承载，为城市用地调控、空间发展政策的制定提供依据。以武汉市主城为实证区，采用1989、1999、2008和2015年4期Landsat遥感影像为数据源，综合空间信息技术、用地扩张量化分析方法研究城市土地利用转换关系，测度建设用地扩张强度、弹性与方向，揭示城市格局时空演变过程。结果表明：1989~2015年间，武汉市主城区土地利用变化以建设用地扩张、未利用地和耕地减少为主，经济增长与建设用地扩张关联度高；主城区建设用地在1999年之后扩张速度明显加快，总体扩张强度逐步加强。建设用地扩张呈现时空不平稳状态，扩张主要集中在以汉阳、青山为代表的城郊过渡带区域，以及硚口、武昌等老城区的更新改造区域，1989~2008年间扩张方向以偏西向为主，2008~2015年间扩张方向以东南向为主，反映城市区域发展阶段的差异和空间开发政策变动的影响。

STUDY ON SPATIOTEMPORAL EVOLUTION OF URBAN EXPANSION——A CASE STUDY OF WUHAN DURING 1989～2015

The spatiotemporal evolution of urban expansion has provided mechanistic information for the regulation of land use and policy formulation of space development, with the changes of land utilization as the carrier. We conducted an empirical analysis on Wuhan downtown area using the Landsat remote sensing images in 1989, 1999, 2008 and 2015. We applied spatial information technology and quantitative analysis of land expansion to study the transformational relationship of urban land use, and measured the expansion intensity, elasticity and direction of construction land, aiming at disclosing the spatiotemporal evolution of urban patterns. The results showed that during 1989-2015, the changes of land use in downtown Wuhan were mainly represented as expansion of construction land, reduction of unutilized land and cultivated land, and high correlation between economic growth and construction land expansion. Since 1999, the expansion rate of construction land in the downtown area has been accelerated apparently, with the gradually strengthened overall expansion intensity. The expansion of construction land was in the status of spatiotemporal instability, concentrating on suburban areas represented by Hanyang and Qingshan, and the transformed area of inner city represented by Qiaokou and Wuchang. The overall urban expansion followed the northwest direction in 1989-2008 and the southeast direction in 2008-2015, demonstrating the different regional development phases of downtown area and the change of spatial development policies.