Áreas potenciais para cultivo de eucalipto na região hidrográfica São Miguel, Alagoas

Abstract

Eucalyptus afforestation in the state of Alagoas has been increasing significantly since 2013, in experimental units and expansions, so that these agricultural and economic changes have a direct impact on the environment. These anthropic alterations to the environment have magnitudes and interferences in the abiotic, biotic and socioeconomic sustainability, necessitating a constant and permanent analysis of the environmental conditions. Therefore, the present study aims to guide and identify the potential areas for eucalyptus cultivation in the São Miguel Hydrographic Region (RHSM-AL), so that this prognosis is a basis for a territorial planning and subsidizes informed decision-making reality in a specialized and measured way. The study area is the São Miguel - Alagoas Hydrographic Region (RHSM - AL), composed of 5 hydrographic basins (Poxim River, Jequiá River, Tabuada River, São Miguel River and River Niquim) and characterized by the historical presence of the sugarcane monoculture and the recent introduction of eucalyptus. The environmental analyzes were carried out based on geoprocessing, which Geographic Information Systems used were the SAGA-UFRJ and the QGIS, under an updated geocoded database of relevant variables to identify this potential, so that 5 environmental cartograms were generated: delimitation of the study area, soil use and vegetation cover, hypsometry and slope. The results of these physiological characteristics, allowed making some considerations about the study area, evidencing a region with strong presence of sugarcane and pasture, predominant territorial extension of altimetric heights of less than 200 m and flat relief. Therefore, to obtain an identification of the potential areas, was used a data integration using the weighted average algorithm, which is the classified by weights and grades. As a final result, he obtained 5 classes of potential: very low (grades 1-2), low (grades 3-4), medium (grades 5-6), high (grades 7-8) and very high (grades 9-10). The first three classes were very fragmented and dispersed along the studied area, totaling 9.4%, the fourth class was a large territoriality, with 57%, and finally, the fifth class occupies 33% of the total area analyzed. It should be noted that, about the environmental legislation, it is not allowed the implantation of this cultivation in all areas with high potentiality, therefore, restrictions are attributed to these areas; and according to the eucalyptus impact studies on water resources, only 20% of each hydrographic basins are tolerated for a minimum impact. The obtained results seek to contribute to the territorial planning and provide support for the decision-making.