SPATIAL DYNAMICS OF SEMIDECIDUOUS SEASONAL FORESTS: CASE STUDY IN THE TURVO SUJO RIVER BASIN IN SOUTHEASTERN BRAZIL, BETWEEN THE YEARS OF 2003 AND 2016

Abstract

ABSTRACT The Agência Nacional das Águas (ANA) states that Brazil faces a water shortage problem since 2012, and it is linked with the conservation of the country’s watersheds directly. It is possible to track the landscape changes and its conservation state through satellite images. This study aims to analyze the spatial dynamics of Semideciduous Seasonal Forest (FES) fragments in the basin of the river Turvo Sujo, in Minas Gerais, southeastern Brazil, between the years of 2013 and 2016, and how this dynamic relates to the terrain aspect. In order to accomplish that, we used images of the Landsat series with geometric, radiometric and atmospheric corrections. For processing those images, samples of five categories of land cover and use were collected from RGB compositions. Maximum Likelihood was used to classify the images, and the overall accuracy, the confusion matrix, and the User’s and Producer’s accuracies per category were later obtained during the validation process. In 2003 the SSE occupied an area of 6.956 hectares, with highly fragmented disposition. Between 2003 and 2016 the native forest increased 42% (about 3.053 hectares of regrowth within 13 years), resulting in a total of 10.009 hectares in 2016. The fragments of Semideciduous Seasonal Forest are more frequently present in the South, Southeast, Southwest and West aspects in both years, 2003 and 2016. However, the forest regrowth a long those years did not follow that evidence, with the regrowth occurring equally in all the exposition faces, except in the plain terrains, that represents only 0,03% of the studied watershed. That is an evidence relevant and positive, which must be monitored, once it is necessary to conserve all terrain aspects for water availability and quality maintenance within watersheds.