Short-term temporal and spatial analysis for post-fire vegetation regrowth characterization and mapping in a Mediterranean ecosystem using optical and SAR image time-series

Abstract

In the present study, the temporal and spatial dynamics of the post-fire recovery of different Mediterranean vegetation types during the three years after the fire event were analyzed, according to different fire severity categories, integrating the use of Synthetic Aperture Satellite Radar (SAR) (Sentinel-1) and optical (Sentinel-2) image time series. The results showed that Mediterranean forest species and shrub/herbaceous species are adapted to fire, with high efficiency in restoring the vegetation cover. Differently, the ecological vulnerability of non-native eucalyptus plantations was found in a lower recovery trend during the observation period. The use of optical short-wave infrared (SWIR) and SAR C-band-based data revealed that some ecological characteristics, such as the woody biomass and structure, recovered at slower rates, comparing to those suggested by using near-infrared (NIR) and red-edge data. An optimized burn recovery ratio (BRR) was proposed to estimate and map the spatial distribution of the degree of vegetation recovery.