利用遥感反演和GIS空间分析等工具,提出了一种基于空间统计特征的城市热岛范围界定方法,并应用该方法分析了1984—2010年杭州市城市热环境的时空演化规律.结果表明:1984—2010年间,杭州市的城市热岛面积增加了8.66倍;杭州城市热岛的空间形态日趋复杂,空间分布由单中心的聚集状态逐渐向多中心的扩散状态发展;杭州城市热环境呈现出由区域低温均衡向区域高温均衡发展的态势.城市热岛的动态变化检测表明,城市扩张是杭州城市热岛发育的主要原因.本文所提方法考虑了城市地表温度的空间相关关系,反映了城市地表温度的全局统计特征,提供的信息更多,也更为客观和准确.通过该方法的推广,有助于解决当前城市热岛研究中研究样本之间缺乏通用性和可比性的问题.
A new method which aims to determine the area of urban heat island (UHI) was pro- posed in this paper based on spatial statistical features by means of remote sensing and GIS spatial analysis tools, and was applied in the spatial-temporal evolution analysis of UHI in Hangzhou, Chi- na. The results showed that the area of UHI in Hangzhou increased 8.66 times from 1984 to 2010. During the 26 years, the spatial structure of UHI in Hangzhou had become more and more complex, and its spatial distribution changed from single-center to multi-center. Generally speaking, the change trend of thermal environment in Hangzhou was turning from low-temperature spatial equili- brium to high-temperature spatial equilibrium. The major cause for the development of UHI in Hang- zhou was urban expansion as it showed in the results of dynamic change detection. This new method considered the spatial correlation of urban land surface temperature (LST) , and reflected the global statistical features of LST. It was more objective and accurate than the conventional methods, and could provide more information, which would help us to resolve the problem of being lack of gene- rality and comparability in the current research.