Assessment of vegetation regrowth and spatial patterns and severity factors of wildfires in wildland-urban interface - the case of the large wildfire in Baião (2019)

Abstract

Portugal is one of the countries most affected by forest fires in southern Europe, with recurrent events and frequent impacts. The demographic and social changes that have occurred in rural areas have driven land neglect in recent years, which, in turn, influences forest management and wildland-urban interface (WUI) areas that are related to fires. Therefore, it is the aim of this study to develop a case study in the municipality of Baião, based on the large wildfire (LWF) of 2019, defining and mapping the WUI areas, as well as evaluate, the recurrence, the GIF severity and in a period of 2 years, the regeneration of vegetation, in areas with different land uses and affected by different severities. The study was organized into 4 stages, being that in the first proceeded to the mapping of fire occurrences, the second of the wildland-urban interfaces, the third the characterization of the recurrence of large fires, the fourth corresponded to the evaluation of the severity of the large wildfire of 2019 and the evaluation of the vegetation regeneration, as a function of land use. The WUI represent 26.7% of the territory of the municipality of Baião, during the years 2001 to 2021 the municipality registered 3 770 fire occurrences. The LWF of Baião burned an area corresponding to 853 ha, the burned area in 2019 presented a maximum number of 12 fires between the years of 1975 to 2019, resulting in a maximum degree of 11 recurrences for the same area. We can verify that 2 years after the LWF, the area occupied by forest and scrub classes, which were hit by high severity, already showed significant levels of vegetation regeneration. With this, the main conclusions consider studies in this line contribute to the understanding of the patterns created by the wildfire in different landscapes, being information valuable for forest managers to understand the consequences (beneficial or not) and plan actions of prevention, restoration, and environmental education.