Dinâmica espacial da degradação ambiental em áreas de mineração no Distrito Aurífero do Lourenço (Calçoene, AP), 2016–2023: análise por sensoriamento remoto

Abstract

Mining has historically been relevant to the Amazon’s economy, but it also ranks among the main anthropogenic activities that cause significant environmental impacts, such as deforestation, soil degradation, and changes in water bodies. In the state of Amapá, the Lourenço gold district stands out as one of the oldest artisanal gold mining centers in the Amazon and the main one in the state, also hosting industrial mining activities of the same mineral. The region is marked by a recent intensification of mineral exploitation, generation of environmental liabilities, and limitations in environmental control and monitoring. Therefore, this study aimed to map and quantify the evolution of degraded areas caused by artisanal mining (legal and illegal) and industrial mining in the Lourenço district between 2016 and 2023. The methodology consisted of a bibliographic survey and land use and land cover classification into seven thematic classes (vegetation, secondary vegetation, exposed soil, water body, altered water body, pasture, and urban area) using supervised classification techniques in QGIS software, based on high-resolution satellite images (5 m) from the PlanetScope platform. The results indicate a significant increase in environmental degradation during the analyzed period, with the total degraded area increasing from approximately 1,698 ha in 2016 to 3,375 ha in 2023, representing an increase of about 1,677 ha and an average annual rate of 239 ha/year, considering legal mining, illegal mining, and industrial mining together. Illegal mining accounted for the highest absolute increase in degraded areas (53% of total degradation), while legalized artisanal mining presented the highest relative degradation rates (43%), and industrial mining showed lower absolute and relative values (5%). A marked reduction in vegetation cover was also observed, reinforcing the need to strengthen monitoring and enforcement actions, particularly regarding illegal mining activities in the region.