極東ロシアにおけるNOAA/AVHRRデータを用いた大規模森林火災特性の比較と改良

抄録

There are two major methods for NOAA/AVHRR-based fire detection. These methods are the threshold method and the contextual method. Threshold method detects fire pixels by comparing the radiant temperature of each pixel to predetermined threshold values. Contextual method detects fire pixels by comparing the radiant temperature of each pixel to its surrounding pixels. In the present study, these NOAA/AVHRR-based fire detection methods were compared and evaluated. And the authors improved the contextual method for Russian Far East. The processes were ; (a) First, conventional contextual method and modified contextual method were compared and evaluated for application to large-scale forest fire, (b) Secondly, modified contextual method and threshold method were compared and evaluated. A burnt area map developed from Landsat/TM data was used to assess and validate the locations of fire pixels detected by each method. The results show that ; (a) modified contextual method was able to detect fire pixels that the conventional contextual method failed to identify, but modified contextual method was inferior to conventional contextual method in fire detection accuracy, (b) the number of detected fire pixels was more and fire detection accuracy was better by the contextual methods than by the threshold method.