Burned Area Detection in the Canadian Boreal Forest Using MODIS Imagery

Abstract

The boreal forest biome is one of the largest on earth,covering 17% of total land area.The major ecosystems within the boreal zone contain more than 30% of terrestrial carbon stores,thus representing a major component of the global carbon budget.Wildfires are a main disturbance factor in the Canadian boreal forests,which play an important role in boreal ecosystems.In this paper,we mapped the forest burned area in Saskatchewan and Alberta of Canada during 2004-2011,using two data sets of Moderate Resolution Imaging Spectroradiometer(MODIS) Land Surface Temperature(LST) and Enhanced Vegetation Index(EVI) imagery at 1 km resolution.The MODIS global disturbance index algorithm(MGDI) was used to detect the forest burned area.It is based on the consistent radiometric relationship between annual maximum LST and the maximum EVI value that occurs after the LST during the same year at every pixel.The performance of the algorithm was evaluated by comparing the results with the MODIS MCD45A1 products and the inventory data from Forestry Bureau of Canada.The results show that the majority of fire events is captured by the MGDI techniques,and the burned area estimated by the fires pixels is better in good agreement with the inventory data than MODIS products.Compared with the Canadian Forestry Bureau data,the average relative error of our algorithm results is only 8.03%,while the MODIS product results is up to 70.53%.The results estimated that the average burned forest area is about 763 600 ha annually,which is about 3.36% of the total forest in this region.A mean annual burned forest is 468 300 ha for Saskatchewan and 295 300ha for Alberta respectively.The Canadian boreal forest fires show a significant interannual variation and severity,the burned scar mainly appeared in the years of 2006,2008 and 2010-2011.Forest burned area mainly concentrated in the ecotone of the Boreal Shield,Taiga Shield,Taiga plains and the Wood Buffalo National Park located at the northeast of Boreal Plains.