摘要
1987年大兴安岭发生特大森林火灾,气象卫星AVHRR(高级甚高分辨率辐射计)图像和陆地卫星TM(专业制图仪)图像记录了这场林火的全过程。气象卫星观测周期短、频度高,但地面分辨力低;陆地卫星观测频度低,但地面分辨力高。两者互相配合,取长补短,是对林火进行实时监测的有效手段。TM第7波段对于探测温度高达1000℃左右的林火十分敏锐;由TM7、4、3(分别赋于红、绿、兰色)合成的彩色图像具有近天然色彩,使图像反映火焰、烟雾、火烧迹地、未烧林地都十分清晰,从而为准确确定火场位置、面积、评估受灾损失及规划恢复与重建工作提供了可靠依据。用灾后第一二年初夏及秋末的TM图像,并与灾前、灾中的TM图像做复合处理,可获得灾后林木恢复变化信息。
In May 1987, a great forestfire broke out at the Mountains of Da Xinan Ling, The fire Lasted nearly a month. Fire-stricken area covers more than 10000 sq. km. During the conflagration, a real-time moni-tor of the fire condition was conducted by using satellite re-mote sensing. More than 40 scenes of Advanced Very High Resolution Radiometer (AVHRR) and 7 scenes of Thematic Mapper (TM) images were processed and analyzed. They provided the timely grasp of fire condition including pre-cise location and spreading di-rection of flames, effectiveness of various fire-suppressing measures. A colour mosaic of 3 neighbouring TM scenes ac-quired on later stage of the fire was generated through digital processing to show the whole fire-affected area. An affliction degree map was drawn up accordingly.After the conflagration, the changes in fire-stricken area have been grasped by using TM images.
