武汉市城区热场变化的遥感检测与影响因素分析

以TM/ETM 热红外波段为基本分析数据,通过数据处理得到武汉市城区及其近郊可对比的热红外像对辐射值,提取了研究区建筑物、绿地及水体等下垫面信息。在此基础上,对研究区1988年和2002年的热场时空分布和变化特征进行了分析,指出研究区热场影响因素按作用大小依次为建筑物、绿地和水体。同时表明,采用热辐射较为稳定的水体DN值对热红外波段数据做规范化处理,所得热辐射相对值具有很好的时空可对比性。

THE DETECTION OF THERMAL FIELD CHANGE IN URBAN AND SUBURBAN AREAS OF WUHAN CITY WITH TM/ETM+DATA AND AN ANALYSIS OF THE AFFECTING FACTORS

The thermal field of urban and suburban areas of Wuhan city was derived from TM/ETM~ thermal infrared data,and the results were qualitatively analyzed.Water bodies have stable and uniform thermal field.By normalizing the thermal infrared bands(DNs of thermal infsared band divided by the mean value of water bodies),the two bands of 1988 and 2002 become comparable with each other in thermal value.With the other bands of the same data set,the basic factors affecting the thermal field,namely buildings,greenbelts and water bodies,were identified by visional interpretation or image processing.Contours of the normalized data were calculated for qualitative analysis of the basic affecting factors.The results show that the effects upon the thermal field gradually decrease in order of buildings,greenbelts and water bodies.