武汉城市群城镇用地扩展的动态模式及其驱动机制

基于遥感和GIS技术获取了武汉城市群3个阶段(1980～1990、1990～2000、2000～2010年)的城镇用地信息，采用景观扩张指数、间隙度指数和相关分形维数分析了该地区城镇用地扩展的基本模式、空间形态演化及其驱动机制。主要结论：（1）城镇用地扩展基本模式呈现差异，第一阶段以边缘式和飞地式扩展为主，第二、第三阶段以边缘式扩展为主；（2）城镇用地空间形态处于演化变动中，第一阶段城镇用地扩展遵循“小集聚、大分散”的特点，城镇用地分布呈现“均一化”，第二阶段城镇用地扩展显著趋缓，增长空间相互分离，以中心城市的孤立扩展为主，第三阶段城镇用地扩展呈现“首位式”“集中化”趋势，武汉市中心性显著增强，核心-外围差别显著，局部范围的空间融合初露端倪；（3）城镇用地扩展经历了多点“开花式”均匀扩展期、散点“离心式”缓慢扩展期和集聚“首位式”快速扩展期，这种差别化的城镇用地扩展模式与空间形态演化主要受国内外发展环境、国家发展战略、城市建设方针以及土地管理政策的综合影响

DYNAMIC PATTERN OF URBAN LAND EXPANSION AND ITS MECHANISM IN WUHAN URBAN AGGLOMERATION

Based on Landsat TM, ETM+, MSS data, we mapped the urban lands in the Wuhan urban agglomeration in 1980-1990, 1990-2000 and 2000-2010 with the application of remote sensing and GIS technology. The paper investigated the dynamic urban expansion pattern, spatial form evolution of urban land and its driving factors during the study period, using the landscape expansion index, lacunarity index and fractal correlation dimension. We found that spatial expansion patterns in the Wuhan urban agglomeration presented different characteristics during different stages. In the first stage, the basic pattern was characterized by edge expansion and outlying expansion, while in the second and third stages the pattern was dominated by edge expansion. The spatial distribution of urban lands exhibited significant fluctuation during the different periods. In detail, during the first decade 1990-2000, the newly increased urban lands followed a dispersed expansion pattern and the spatial distribution in relation to urban land was characterized by homogenization. In the second decade, urban land expansion decelerated significantly and urban land use expansion intensified along isolated central cities. During the third stage, urban land expansion showed a trend of high primacy and concentration; the spatial differences of urban land distribution were enhanced significantly between Wuhan and its periphery areas. Overall, Wuhan urban agglomeration has experienced an even dispersed expansion in 1980-1990, a slow centrifugal scattered expansion in 1990-2000, and a rapid aggregated highly primate expansion in 2000-2010, respectively. These spatiotemporal differences were found to be closely related to foreign and domestic development environment, national development strategy, urbanization guidelines and land management policies. However, it is worth noting that the dominant driving factors varied between different decades studied