Wildfires are an important subject of study due to their multiplicity of effects on people, heritage, and the environment. In this paper, we analyse different aspects related to a Large Wildfire (LWF) that occurred in 2019. For this purpose, the recovery of the vegetation is analysed. To carry out the study we used Sentinel 2 satellite images and performed the application of spectral indices NBR and their multispectral variation dNBR for the evaluation of the vegetation regeneration after 6 months, 1, and 2 years after the fire. Image processing was performed on the GEE platform. The LWF burned an area corresponding to 853 ha in a single occurrence, which was the third-largest LWF in that year. Regarding the evaluation of vegetation regrowth, in the evaluation of vegetation regeneration after 6 months of the wildfire, we identified that 40.7% of the area showed high vegetation growth and 20.8% low vegetation growth, 22.4% had a response equivalent to a burnt area, and 17.8% of the area still has the characteristics of a burnt area. One year later, we identified that 60.83% of the area showed high vegetation growth, 20.61% low vegetation growth, 14.97% had a response equivalent to an unburnt area, and 3, 59% of the area still has the characteristics of a burnt area. However, within two years after the wildfire, 76.27% of the area registered high vegetation growth, 12.15% low vegetation regrowth, 8.97% continued with the spectral behaviour of an unburnt area, and 2.61% with burnt area characteristics. Even with good vegetation recovery rates, it is urgent to develop studies on the multiple and varied impacts of fires. Two years after the fire, the area occupied by the forest and brush classes, already showed significant levels of vegetation regrowth, corresponding to approximately 100% of the area occupied by this class.
dos Santos, Sarah,Bento-Gonçalves, António, Vieira, António
University of Minho
ID Abstract: 973