基于改进TAE算法的城市热岛信息提取技术  

The technology based on improved TAE algorithm to extract the information of urban heat island

作　　者：杨波[1] 刘宇鹏[1] 马苏[1] 曾发明[1] 

机构地区：[1]湖南师范大学资源与环境科学学院GIS研究中心,长沙410081

出　　处：《地理研究》2011年第5期871-878,共8页Geographical Research

基　　金：国际科技合作重点项目(2007DFA90500);湖南省自然科学基金(10JJ3022);湖南师范大学青年优秀人才培养计划;地图学与地理信息系统湖南师范大学校级重点学科资助

摘　　要：在使用遥感数据提取煤火热异常信息的TAE算法的基础上,根据城市热岛特点对算法进行了改进,提出了针对城市热岛研究的Urban-TAE算法,即U-TAE算法。该算法使用不同范围的滑动窗口来探测整幅图像,根据稳健估计的方法设定地表温度高于全部像元以及窗口内像元温度统计均值+标准差的像元为热异常像元,并将滑动窗口的范围设置在5×5～151×151个像元之间,根据像元被记为热岛像元的次数是否为0来区别非热岛区与热岛区,在热岛区域内根据次数的多少来决定热岛强度,具有动态阈值的特点和无偏特性。研究结果表明,在城市热岛范围的提取上,2001年长沙市热岛面积在55.31 km2至68.35 km2之间;在城市热岛的强度分析上,宏观尺度的研究应选用较大的窗口来体现城-郊热岛关系以及热岛发展的总体趋势,而小窗口在微观分析城区内热岛的具体分布、与下垫面的关系以及驱动因子方面较有优势。与传统方法相比,U-TAE算法使得不同时相的实验结果具有可比性。The urban thermal anomaly extraction（U-TAE） algorithm was proposed for the study of urban heat island,which was evolved from the TAE algorithm for thermal anomalies extraction of underground coal fires.The U-TAE algorithm detects the entire thermal infrared image by moving windows with different sizes,and the key of this robust algorithm was to set up thresholds for pixels with land surface temperatures（LST） higher than mean plus standard deviation.Mean and standard deviation were calculated from all pixels and those pixels in the moving windows（scope from 5×5 to 151×151 pixels）.This algorithm can distinguish UHI areas from background areas according to the cumulative times of pixels,and determine UHI intensity according to the cumulative times in UHI areas.Cumulative times of zero are background areas and the others are UHI areas.This U-TAE algorithm has dynamic thresholds and unbias characteristics.Results showed that the heat island areas were between 55.31 km2 and 68.35 km2 in Changsha in 2001.In UHI intensity analysis,the UHI studies at macro-scale should use larger moving windows to reflect the relationship between urban and rural areas.Micro-scale studies should use smaller moving windows to analyze specific distribution of UHI,underlying surface and driving factors.Compared with traditional methods,U-TAE algorithm makes the results comparable in different time periods.

关 键 词：遥感 城市热岛 TAE算法 滑动窗口 

分 类 号：X16[环境科学与工程—环境科学] P237[天文地球—摄影测量与遥感]