中国与美国大都市区城市内部土地覆盖结构时空差异

城市内部土地覆盖结构对城市生态服务功能和人居环境质量产生重要影响。中国与美国不同发展阶段城市不透水地表和绿地时空分布格局存在显著差异。本文基于Landsat TM/MSS影像获取1978、1990、2000、2010 年城市内部土地覆盖和不透水地表分类信息，监测并比较中国和美国六个特大城市扩展时空动态、土地覆盖结构差异及城市不同功能区特征。研究表明，在过去30 多年以来，中国城市以相对紧凑形态发展，美国城市较为离散；美国三大城市植被所占的比例是中国的2.21 倍；中国城市内部结构土地利用功能类型更加复杂，不透水地表密度更高，而美国城市CBD和居住区功能相对独立，特别居住区以镶嵌式低不透水地表和高绿地比例结构为主。

Spatio-temporal characteristics of intra-urban land cover in the cities of China and USA from 1978 to 2010

Urban land cover has major impacts on urban ecosystem service and inhabitant living environment. Chinese cities' spatio-temporal distribution of impervious surface area and green land shows more remarkable differences than that of USA. This study focused on monitoring and comparing the spatio-temporal dynamics, land cover patterns and characteristics of urban functional regions in six cities located in China and USA, based on Landsat TM/MSS images obtained in 1978, 1990, 2000 and 2010. The study indicated that the three major cities in China were developing with compact forms, but the three major cities of USA have presented dispersed forms during the past 30 years. The proportion of vegetation land of the three cities in the USA was as much as 2.21 times of that in the three China's cites. Land use types of Chinese cities are more complicated with a higher density of impervious surface area. In contrast, the CBD and living areas of American cities were covered by low impervious surface area and high rate of green land, which were relatively independent. This study can make contribution to urban planning and administration for both China and USA.