Evaluation of the groundwater recharge potential using GIS multi-criteria data analysis: a case study from district of Itabira, Minas Gerais, southeastern Brazil

Abstract

Knowledge about the groundwater potential is an important tool to sustainably manage groundwater exploitation. In this context, based on the Geographic Information Systems (GIS) and multicriteria analysis by the Analytic Hierarchy Process (AHP), this study had the objective of mapping the groundwater potential of the district of Itabira, Minas Gerais, which is one of the largest mining regions in Brazil. The evaluation of the regional groundwater potential was based on thematic maps of land use and cover, soil, geology, slope, lineament density, and drainage density. From the evaluation of these parameters and their classes, weights were assigned by the AHP method, according to the influence of each one with regard to favoring water infiltration and aquifer recharge. The thematic maps were integrated in a GIS environment, generating a groundwater map of the district divided into five classes of groundwater potential (very low, low, moderate, high, and very high). In about 64% of the territory the potential for groundwater occurrence was very low to low and from moderate to very high in about 36%. The groundwater potential map showed that 64.42% of the district of Itabira has very low to low potential indices, mainly due to a number of regional characteristics that make aquifer infiltration and recharge difficult and occur in large areas of the territory.