多时相影像福州市不透水面对城市地表温度的空间分布研究

随着城市化进程的加快,城市热力场也随之发生变化,从而影响着城市区域环境、社会经济以及社会环境。由于NDVI具有季相变化的不稳定性,本研究采用两个时相TM/ETM+影像分析福州市及其周边地区不透水面对热力场的时空分布变化状况。为了获取精确的城市不透水面信息,本实验采用NDVI二元法结合2000年同区域的IKONOS影像提取不透水面信息。通过定量分析不透水面百分比、NDVI与地表温度的关系,得出不透水面百分比与城市地表温度呈线性相关,其相关系数在0.7左右;尤其30%以上的不透水面对地表热环境的空间分布影响最为突出,因此,相对于不稳定的NDVI而言,不透水面信息能更好地反映城市热环境的空间分布状况。

Study on Spatial Distribution of Land Surface Temperature Effected by Impervious Surface of Multi-temporal Images in Fuzhou City

Using time-phases TM/ETM＋ imagery,this paper examines the impervious surface and its impact on thermal field in Fuzhou city of Fujian province,China.Comparison has been done to the fraction impervious surface and the normalized difference vegetation index（NDVI） in reflecting thermal field in urban area.The NDVI binary method was used to combine with IKONOS imagery in 2000 for extraction of impervious surface.The relationship between impervious surface,NDVI and land surface temperature（LST） was quantitatively analyzed.Our results showed that the impervious surface has a linear correlation with LST,with coefficient of 0.7.In particular,more than 30% impervious surface has an important effect on the spatial distribution of the thermal environment.Therefore,the impermeable surface area could be a better indicator to reflect the spatial distribution of heat flux in urban environment.