Análise da dinâmica de focos de calor na reserva biológica Nascente da Serra do Cachimbo - Sudoeste do Estado do Pará

Abstract

The Reserva Biológica Nascente da Serra do Cachimbo is a conservation unit governed by the Sistema Nacional De Unidades de Conservação (SNUC) classified as Integral Protection, in which it is not allowed to visit or directly use its natural resources. Even being a unit characterized as integral protection, this unit has been receiving alerts from the Instituto Nacional de Pesquisas Espaciais (INPE) of large numbers of hotspots in the area of this 1reserve, indicating abnormalities. The use of geotechnologies, especially remote sensing, are of great help for several studies in the environmental area. In order to analyze the factors that encourage the dynamics of hotspots in the reserve, analyses of soil use and coverage were performed in order to evaluate the growth of deforestation in the area; analysis of the variables surface temperature and precipitation, which will give basis to possible indications of risk aggravating factors, and analysis of fire susceptibility using the normalized difference index (NDVI). The results of the land use and cover analysis showed a great dynamic of uses on the coverings present in the reserve, the forest suffers with the actions of deforestation and the campinarana areas with the dynamics of fires present by the openings of large areas of exposed soil. The temperature analysis showed that the variation in soil cover will directly influence its variation, higher temperatures were found in areas with less tree cover, áreas with removal of cover and exposed soil. The precipitation variable showed a seasonality in relation to the months of the year, showing large amounts of rainfall in the months from October to April and droughts from May to September, these being the most critical months. In addition, it was possible to describe that the years with the longest precipitation are related to the number of hotspots in the reserve, and it can be inferred that 2017 was considered the driest year, due to the large number of hotspots present in this year. For the analysis of NDVI, the typologies found in the use and coverage of the soil were observed: forest, dense campinarana and open campinarana, analyzing only the intervals of NDVI considered of "high" and "moderate" susceptibility, showing the most vulnerable areas to fire. The Forest class demonstrated great vulnerability in its area of contact with other typologies and áreas close to deforestation, while areas of dense and open campinarana showed extremely low intervals concluding that these areas are highly susceptible to fire, and may be one of the reasons for large fires in these areas.