摘要
1987年5年,大兴安岭地区发生特大森林火灾,笔者使用TM图象进行了火情监测,对救火指挥部了解火场情状,部署救火活动,估算灾害损失,制订重建规划等起到较重要作用。 林火温度可达1200—1500°K,这种温度的黑体的辐射峰值为1.93—2.41μ,正与TM7波段的光谱响应范围(2.08—2.35μ)一致,故该波段很适于林火监测,以TM7.4.3赋红、绿、兰色合成的图象具近天然彩色。 与气象卫星图象相比,TM具有更高的空间分辨和更佳的几何保真度,故能更精确确定火场位置。数字镶嵌成的灾区全景图算出过火总面积达126万公顷,并据此绘制出灾害等级图。 比较分析了灾前、灾中、灾后该地区的TM图象,可以看出:轻灾区大部分林木复苏,中、重灾区阴坡长了许多草木灌木,某些重灾区阳坡的局部地段已出现水土流失迹象。
In May, 1987, huge Forest Fire raged in Da Xin An Ling, North-East of China. We monitored the fire area using Landsat TM data during and after the fire. The interpreation results and findings were very useful in decision making for fire-suppressing activites, loss estimation and regeneration of the forest.Forest fire temperature may reach as high as 1200-1500°K, which correspond to black body peak emittance at 1.93-2.41 μ. TM 7 spectral band (2.08-2.35) suits best for fire monitoring. TM 7, 4 and 3 band combination and color rendition in red, green and blue sequence provides image in nearly natural color.TM data were routinely received and processed during the fire period. In comparison with AVHRR data, TM has much higher resolution and geometric fidelity. It provided information crucial to fire-suppressin activites. It showed the actual status of the whole area, helped to take emergent measures to prevent fire from spreading to Innermogolian primeval forest, helped to decide not to build additional outer layers of fire breaks, strongly suggested by local authorities and to announce the end of the fire. A mosaic image of the whole fire-affected region was digitally made, the degrees of forest damage were classified and mapped and the fire affected area was calculated to be 1.26 million heactares.TM scenes, before, during and after the fire, were studied. Findings show that the lightly damaged area has basically regenerated, the moderately damaged area and the shady slope of the heavily damaged area are mainly covered by bushes and grasses, while the sunny slope of several heavily damaged areas shows sign of loss of soils.
出处
《宇航学报》
EI
CAS
CSCD
北大核心
1990年第1期7-17,共11页
Journal of Astronautics
