Quantification of the severity of fires in an environmental protection area in Mato Grosso/Brazil

Abstract

The Cerrado (Brazilian Savanna), in addition to being the second-largest biome in Brazil, is also classified as a pyro-biome, which means a biome adapted to natural fire. In recent years, research on the use of fire in the Cerrado has grown significantly in the academic community. In September 2020, a fire of unknown anthropogenic origin occurred in the Environmental Protection Area of the Headwaters Cuiabá River (APACRC), with an estimated duration of more than 15 days. Due to the extent and regularity of the affected area, predominantly of savanna formation, this event sparked great interest for investigation. As a result, it was proposed to classify and quantify the severity of the fires in the APACRC Conservation Unit using the NBR (Normalized Burn Ratio) spectral index and its variations. To conduct the analysis, satellite images were obtained from before the fire (September 5, 2020) and during/after the fire (September 18, 2020). The NBR index was calculated for the pre- and post-fire periods to identify the degree of fire severity. In total, 18,870.57 hectares were impacted by the fire, of which 87.51% were of savanna formation, 11.78% forest, and 0.71% grassland. The analysis of the dNBR index revealed that, although contributing to the spread of the fires, most areas were affected with low severity, suggesting that regeneration damage may not be as severe in this situation.