基于NOAA/AVHRR热红外数据的城市热岛强度年内变化特征

采用ENVI/IDL编程技术,实现NOAA/AVHRR数据的校准、几何纠正、云污染识别与剔除、影像特征统计与输出等过程的批处理自动化操作。并以济南市中心城区为例,通过2005~2006年间获取的白天NOAA/AVHRR影像热红外波段调查了济南市区城市热岛强度的年内变化规律与过程。研究结果表明：① 济南市区全年大部分时间存在热岛现象,4~9月份城市热岛效应较为明显,尤以5、7、8月为甚。② 全年城市热岛平均强度2.77℃,最强的热岛效应出现于7月下旬至8月中旬间。③ 从季节分布来看,济南市区夏季热岛效应最明显,春季次之,秋、冬两季较弱。④ 城市热岛强度与城、郊地表温度存在正相关关系,但相关程度较差。

Intra-annual Characteristics of the SUHI Intensity from NOAA/AVHRR HRPT Data Using ENVI in Batch Mode

It demonstrates a procedure for rapidly estimating the intensity of surface urban heat island (SUHI) from direct-downloaded NOAA/AVHRR HRPT data using the ENVI image analysis software operating in batch mode.The processing stream provides for reading level-1b data,calibration,geometric correction,sub-setting imagery,calculation of surface temperature,cloud screening and image statistics.Then,this procedure was used to investigate the intra-annual characteristics of daytime SUHI intensity in Jinan city,Shandong province.The results show that:① SUHI phenomena exist over a majority of months throughout the year,especially from April through September;② the mean SUHI intensity is 2.77℃ and the most intense effect (more than 10℃) occurs during the period from the last ten-day of July to the middle ten days of August;③ the significant SUHI mainly appears in the summer,the spring takes second place,and the UHI in the autumn and the winter seems not obvious;④the SUHI intensity correlates positively to urban and suburban surface temperature with low regression coefficients.