How can satellite sensors be used to map burned areas?
Since forest fires exceeding 10 km² account for more than 95% of the annual burned area in Canada, 1-km resolution satellite imagery is effective for mapping the vast majority of burned areas. A technique has been developed at the Canada Centre for Remote Sensing (CCRS) that allows burned forest to be mapped at annual intervals across Canada (Fraser et al. 2000). The method works by combining an annual AVHRR hotspot map with observed annual changes in a vegetation index from SPOT VGT. The vegetation index is compared for each pixel from one year to the next (e.g., September 1998 and September 1999). Pixels with a significant drop in the index that are spatially coupled to an AVHRR hotspot are mapped as being burned. This technique is used to provide a coarse-resolution burned area product for Canadian forest at the end of each forest fire season. A separate algorithm has been developed to map burned areas at 30-m resolution using single Landsat TM images. The procedure has been used to
