Dynamics of active fire data and their relationship with fires in the areas of regularized indigenous lands in the Southern Amazon

Abstract

An increase in active fire data in the Amazon puts the entire international community on alert, as they may result in fires and deforestation. Thus, this study aims to present the dynamics of active fire data and their relationship with the fires in 16 Regularized Indigenous Lands (RILs) located entirely in the state of Rondônia, in the southern amazon. The entire historical series of active fire data (from 1998 to 2020) were obtained to achieve the objectives, and nine Landsat-OLI scenes from September 2020 were processed. The active fire data dynamics revealed that the correlation coefficient between the total number of active fire data in the immediate surroundings (10 km) and the number of active fire data within the analyzed indigenous land areas was higher than 0.7. This means that the variation in the number of fire outbreaks within indigenous lands can be explained by the number of outbreaks occurring outside them. Image processing revealed 11 classes of land use and land cover with an overall accuracy of 92%. Based on the mapping of land use and cover for the nine Landsat scenes, it is possible to verify that the burnt area totaled 3,943.50 km2. Besides, 953.90 km2 (24.19%) were located entirely within the indigenous lands, mainly on the Massaco and Uru Eu Wau Wau indigenous lands. By analyzing the density of active fire data, it is possible to verify that most of the outbreaks are located at the edges of the RILs. This shows that these areas work as a barrier to the spread of fire in the South of the Brazilian Amazon. Thus, despite the identification of regions burnt within indigenous lands, the study concluded that RILs are essential for protecting the Amazon's native vegetation.