Avaliação de áreas de regeneração do cerrado a partir de dados espectrais: estudo de caso na sub bacia hidrográfica do baixo rio das mortes

Abstract

The present dissertation addresses the dynamics of land cover and use in the Brazilian Cerrado, a biome that represents approximately 24% of the national territory and hosts a rich biodiversity. The research focuses on the eastern region of the state of Mato Grosso, which has undergone intense transformations since the 1970s, driven by the demand for agricultural commodities and government incentives. Although the Cerrado has significantly lost part of its natural vegetation cover, it has shown high levels of natural regeneration, indicating its resilience to human impacts. Understanding land cover and use changes in a country with continental dimensions like Brazil requires remote sensing mapping initiatives. The study uses remote sensing data and vegetation index (EVI and NDVI) to analyze the regeneration of natural vegetation cover between 2000 and 2023 in the Baixo Rio das Mortes Basin. The results indicate a significant increase in areas dedicated to soybean cultivation, which grew by 1,105.13%, and a substantial conversion of pastures into cultivation areas. Additionally, it was found that less than 1% of the secondary vegetation of the BHBRM remained unchanged, highlighting fragmentation and loss of ecological connectivity, factors that compromise ecosystem resilience. The evaluation of the spectral index time series, EVI and NDVI, from 2001 to 2023, indicated growth in average values during both dry and wet periods, except for the Submontane Semideciduous Forest formation. Moreover, through the spectral response of the indices, it was possible to evaluate possible disturbances related to fires, selective logging, water stress, among others. The analysis reveals that the seasonal productivity of secondary vegetation is strongly linked to the hydrological cycle, with notable variations between Forest and Savanna formations. This research concludes that continuous monitoring and sustainable management strategies are essential to mitigate the impacts of agricultural expansion and preserve the biodiversity of the Cerrado.