Burned areas are characterized by deposits of charcoal and ash, removal of vegetation, and alteration of the vegetation structure (Pereira et al. 1997, Roy et al. 1999). The MODIS algorithm used to map burned areas takes advantage of these spectral, temporal, and structural changes (Roy et al. 2005a). It detects the approximate date of burning at 500 m by locating the occurrence of rapid changes in daily surface reflectance time series data. The algorithm maps the spatial extent of recent fires and not of fires that occurred in previous seasons or years.
1 year of MCD45A1 burned areas; the day of burning is represented using a rainbow scale and is overlaid on MODIS surface reflectance to provide geographic context. Click on the image to see a full scale version.
August 2007 fires in Greece, as mapped by the MCD45 product. Click on the image for a high resolution version.