Diagnóstico de áreas de garimpos, por meio da análise de classificação, na Terra Indígena Kayapó, sudeste paraense, no período de 2014 a 2021.

Abstract

The Indigenous Lands, despite being essential for the preservation of the environment, are threatened by increasing deforestation in their regions, caused mainly by illegal mining activities. Thus, we aimed to conduct a temporal analysis of the progress of these activities, between the years 2014 and 2021, in the Kayapó Indigenous Land, in addition to verifying the situation of these mining regions, aiming to have a basis to know which of them operate legally and which ones go through prohibitive processes. The methodology consisted first of a data survey of the region and, subsequently, the Land Use Classification process was started, using the Supervised "pixel by pixel" model. In all, seven classes were defined, being four macro classes, identified as level 1 classes (1 - Forest; 2 - Mining; 3 - Other Pressure Vectors; 4 - Water Bodies) and three micro classes, identified as level 2 classes (1.1 - Forest Formation; 1.2 - Savannah Formation; 1.3 - Non-forested Natural Formation). The algorithm used for the classification was the Spectral Angle Mapper, with the aid of the Semi-Automatic Classification Plugin, in which the spectral analysis of the classes was also performed, available in the QGis software. The classification accuracy test, for the analyzed years, was estimated from the Kappa Index and the confusion matrix. The data regarding the situation of the mining regions were obtained from the platforms Mining Geographic Information System (SIGMINE), belonging to the National Mining Agency, in which the presence of regulated regions was observed, and MapBiomas Alerta, in which, between the years 2018 and 2021, the presence of embargoed regions and other possible actions, by the Public Power, in progress, were observed. For all years, acceptable Kappa and Confusion Matrix indexes were detected. From 2014 to 2021, 951, 1167, 2047, 2424, 2577, 4136, 5137 and 7300 hectares of mining areas were identified, respectively. Of the total identified for the year 2021, according to SIGMINE, only 773 hectares are regulated. In MapBiomas, between the years 2018 and 2021, only 24 hectares with illegal mining activities have been embargoed, and no other forms of ongoing penalties have been detected for these areas. It is also worth noting the data regarding the other anthropic actions identified in the Kayapó IL, between the period studied, which increased from 711 hectares to 3852 hectares. The study concluded that there has been an excessive growth of mining activity in the Kayapó IL, directly impacting on the reduction of the flora. This work serves as a signpost for the need to carry out the isolated mapping of other Protected Areas, aiming at a more detailed study on the growth of deforestation in these regions.