Análise da fragilidade ambiental em uma microbacia hidrográfica na Região Sudoeste do Piauí

Abstract

Land degradation and desertification are environmental problems that pose significant challenges worldwide. In Brazil, especially in the semi-arid region of the Northeast, these issues are intensified by a combination of natural and human factors. Desertification compromises soil quality and affects essential ecosystem services, such as food and water production. To address these problems, it is crucial to understand the causes of degradation and the interaction between natural and anthropogenic factors, enabling the identification of vulnerable areas and the creation of effective mitigation and recovery strategies. The main objective of this study was to characterize the levels of environmental fragility in the southwestern region of the state of Piauí, focusing on the Gilbués Desertification Center, between 1985 and 2015, using a multicriteria analysis that integrates geo-environmental and anthropogenic factors. The aim was to understand the processes of environmental degradation and provide subsidies for mitigation strategies. Geoprocessing techniques were applied to assess land cover in the micro-basin, using medium-resolution images to analyze land use and land occupation during the analyzed period. For fragility mapping, cartographic bases of soil, lithology, slope, vegetation, and land use were reclassified and normalized for the use of multicriteria analysis. Weights were assigned based on similar studies. The results showed an increase in exposed and moderately exposed soil, with a decrease in moderately conserved areas, as well as a growth in areas with high vulnerability to erosion