Mapeamento da vulnerabilidade da área diretamente beneficiável do Canal do Sertão Alagoano

Abstract

Environmental analysis is essential for understanding landscape transformations and supporting natural resource planning, especially in semi-arid regions where environmental systems are more fragile. In the Sertão and Agreste regions of Alagoas, Brazil, irregular rainfall and recurrent droughts intensify socio-environmental vulnerabilities, reinforcing the need for studies that integrate natural and human factors. In this context, the construction of the Canal do Sertão Alagoano, a water infrastructure project designed for multiple uses such as irrigation and human supply, has promoted significant changes in land use and environmental dynamics in directly benefited areas. This study aimed to evaluate landscape changes and the socio-environmental vulnerability of soils in this region, based on the hypothesis that inadequate irrigation practices may intensify degradation processes, particularly soil erosion. The methodology integrated geoprocessing, remote sensing, and multicriteria analysis within a GIS environment. A multitemporal land use and land cover mapping was carried out for the years 2000, 2010, and 2024 using MapBiomas data, revealing agricultural expansion, urban growth, and increased pressure on natural resources. Pedological mapping was refined using Embrapa soil data, allowing the differentiation of soils with distinct susceptibility to degradation. Soil vulnerability was assessed through an adaptation of the Crepani methodology combined with the Analytic Hierarchy Process (AHP) and fuzzy logic, considering geology, geomorphology, slope, soil classes, and land use. Results indicated a predominance of medium vulnerability areas, characterized by unstable equilibrium, and high vulnerability zones associated with shallow soils and greater anthropogenic pressure. Although the Canal do Sertão has contributed to regional socioeconomic development, it has also intensified environmental pressures, highlighting the need for territorial planning and conservation practices to ensure sustainable soil use in the semi-arid region of Alagoas