Sensoriamento remoto na análise temporal da desertificação no município de Gilbués-PI

Abstract

Desertification is a phenomenon that is of concern to the modern societies, because despite the fact that this problem exists for some time, only now at the end of the XX century and the beginning of the XXI century has gained prominence. This process reaches thousands of people throughout the world and has been the target of several studies with different methodologies to try to understand it. Currently, with the advances of computational resources and the geosciences, there are a range of tools to support the studies about the earth. On the face of it, the use of Remote Sensing comes adding fidelity to the results of studies of geoenvironmental. The aim of this work was to perform the mapping of the areas under process of desertification in the municipality of Gilbués, state of Piauí, as a way to subsidize the evaluation of the transformations in the use and cover of the land and understanding of the phenomenon during the last 30 years. For this, was performed supervised classification and NDVI technique using Landsat 5 and 8 satellite images for the period 1986, 1996, 2006 and 2016. The mapping of the land use of the municipality showed that the main transformations occurred in the region were increased areas of exposed soil and agricultural to the detriment of vegetated areas. The temporal analysis showed that there was expansion in recent years, mainly in its central region that it became more and more intense. Through the NVDI, it was noted the changes that have occurred especially in the areas not vegetated and vegetation sparse. The results were satisfactory since the goals set have been achieved.