Multidecadal satellite-derived Portuguese Burn Severity Atlas (1984 -2022)

The Portuguese burn severity atlas (1984 -2022) provides satellite-derived burn severity estimates of each historical fire with its start and end dates recorded and larger than minimum mapping units of 500 ha for fires before 2000 and larger than 100 ha for fires after 2001 in Portugal. The fire perimeters and dates are provided by the Instituto da Conservação da Natureza e das Florestas (ICNF) (https://sig.icnf.pt/portal/home) with corrections applied on their dates. Mainly Landsat imagery was applied for creation of this atlas, except for 2012, for which imagery from Terra abroad Moderate Resolution Imaging Spectroradiometer (MODIS) is used. The burn severity indices applied within this atlas are differenced Normalized Burn Ratio (dNBR), Relative differenced Normalized Burn Ratio (RdNBR), Relative Burn Ratio (RBR), and index combining dNBR with enhanced vegetation index (dNBR-EVI). Since 1984 to 2022, the total burned area recorded in Portugal is 4.92 million ha. Only valid fires, which are fires equal to or larger than the minimum mapping units with start and end dates, were considered for the burn severity estimates. The total area of valid fires is 3.19 million ha. The Portuguese Burn Severity Atlas provides estimates for 3.11 million ha, accounting for 63% of all fires and 97% of valid fires. The Portuguese burn severity atlas is organized in subfolders, each entitled as the corresponding year and containing shapefile, maps and a table with details on pairs of images used for burn severity estimates. Within each subfolder, the following data are stored: the annual fires’ perimeters shapefile (.dbf, .prj, .shp, .shx) dNBR map (.tiff) RdNBR map (.tiff) RBR map (.tiff) dNBR-EVI map (.tiff) confidence map: average “SUITABILITY in each pixel within the area of the fire (.tiff) comma separated value (.csv) file containing details on the pair of images used for burn severity estimates (year, ID, iteration number, pre-fire time lag(day), pre-fire cloud%, pre-fire suitability (%), post-fire time lag (day), post-fire cloud%, post-fire suitability(%), confidence in the iteration(%), area with dNBR estimation(ha), area of fire (ha), fire i number (to refer in GEE code), dNBR offset value, RdNBR offset value, RBR offset value, and dNBR-EVI offset value). To the best of our knowledge, Portuguese Burn Severity Atlas is the first open access atlas providing burn severity estimates of historical fires for an entire European country, in this case, Portugal, with 38 years of coverage. Target audience who can benefit from this atlas can be policymakers at national levels, field managers, project managers, and agency and academic researchers.