Abstract
About 264 ha of forest area in the southern part of the Miyajima Island was burnt mosaicly in March, 1984. It was not easy to estimate the area damaged by fire. The availability of Landsat MSS data at the estimation of burnt area of both forest canopy and undergrowth was examined. The mesh data about the ratio (BR, %) of burnt area to the total one and ratio (R, %) of illuminance on the ground surface to vertical flat to sun radiation were estimated based on ground survey and geographical map, respectively. The relation between R and Landsat data showed that illuminance (digital number, DN) of Band-6, 7 was separated into three groups, i. e., forest (BR=0), middle damaged (20 ≤ BR<80) and heavy damaged (80 ≤ BR) areas (meshes), while there was little difference in the case of Band-4, 5. DN of Band-6, 7 in the forest and middle damaged areas increased in proportion to R. The fact meant that DN of Band-6, 7 was in need of the geographical correction based on the linear relation between them. There was closely negative linear relation between corrected DN (DN') of Band-6, 7 and BR. It suggested that BR could be derived from the DN'. The burnt area (meshes) was classified into five grades of burnt ratio based on the DN' of Band-7. The area of burnt both forest canopy and undergrowth was calculated at 165.0 ha and also that of burnt only undergrowth was estimated at 99.4 ha from the classification map. These estimated areas by Landsat MSS data were closely coincided with those obtained by the ground survey.
