不透水地表盖度视角下中美城市群空间结构对比——以“京津冀”与“波士华”为例

将城市不透水地表盖度产品应用于城市群空间结构研究具有重要价值。本文基于多源遥感数据提取了“京津冀”与“波士华”城市群近40年（1972-2011年）亚像元级不透水地表专题信息,构建了城市群空间结构对比分析数据集;并引入引力模型和景观格局理论,利用引力指数、景观格局指数以及空间结构参数等,采用地理信息系统空间分析方法,从城市群与城市两个尺度对城市群空间结构进行了对比研究。结果表明：① “京津冀”城市群不透水地表快速增长,而“波士华”城市群较为稳定;② “京津冀”城市群空间结构经历了城市孤立发展阶段、双核心城市群阶段、城市群组阶段以及城市群网络化阶段,“波士华”城市群空间结构较为稳定,空间结构呈现出“点—轴”带状分布;③ 中国城市不透水地表盖度“高—高”聚集区呈现出典型团块状“摊大饼”形态,而美国城市呈现出一种“多中心集聚、分散成组”的态势;④ “京津冀”城市群生态、生产与生活用地不透水地表面积占比均高于“波士华”城市群。最后,基于两国城市群空间结构的对比结果,从空间布局优化角度对“京津冀”城市群的发展提出了初步建议。

Spatial structure comparison of urban agglomerations between China and USA in a perspective of impervious surface coverage: A case study of Beijing-Tianjin-Hebei and Boswash

It is important to apply impervious surface product to the study of urban agglomeration spatial structure. Under the background of China's rapid urbanization, study on comparative analysis of urban agglomerations spatial structure between China and USA can provide policy proposals of urban agglomeration space optimization for Chinese government. Taking Beijing-Tianjin-Hebei (BTH) and Boswash as study areas, firstly, this paper maps the extent and density of impervious surface for BTH and Boswash respectively in seven periods of 1972, 1982, 1991, 1995, 2001, 2006 and 2011. Furthermore, at different scales of urban agglomeration and metropolitan region, landscape pattern index, gravitational index and spatial analysis were used to analyze differences of spatial structure between BTH and Boswash. The results showed that (1) impervious surface area increased rapidly in BTH, while it remained stable in Boswash. (2) BTH spatial structure had experienced different periods including isolated city development, dual-core city development, group city development and network-style city development, while Boswash spatial structure was more stable, and its spatial pattern had shown a "point-axis strip" feature. (3) The spatial pattern of high-high assembling region of impervious surface had showed a "standing pancake" feature in BTH, while a "multi-center gather and disperse group" in Boswash. (4) All of the percentages of impervious surface area in ecology, living, and production land in BTH were higher than those in Boswash. At last, from the perspective of urban agglomeration space optimization, the development proposals for BTH were proposed.