Compartmentalisation and Hydrogeological Parameters of the Karst Aquifer System in Central Region of Minas Gerais State, Brazil

The Environmental Protection Area of Lagoa Santa Karst (EPA) is a critical karst region in Brazil, renowned for its rich biodiversity and archaeological significance, including discoveries by researchers such as Peter W. Lund and the oldest human skeleton in the Americas, Luzia. However, the region faces threats from rapid socioeconomic and industrial development, stressing its vulnerable aquifer systems. This study updates the hydrogeological conceptual model for the EPA using well log data, map algebra and hydrodynamic parameters obtained through the Agarwal (1980) recovery method . It builds on models by De Paula (Conceptual Model in Pelitic-Carbonate Aquifers in the Lagoa Santa Karst APA Region, MG, 2019) and refined by Dantas et al. (Journal of South American Earth Sciences, 2023, 123, 104219), reassessing the boundaries of various aquifer units. Horizontal compartmentalisation in the karst-fissured aquifer was achieved by combining transmissivity and porosity data, while vertical separation was determined based on water entry density and productivity, identifying four zones of increased karstification. In the fissured aquifer, vertical limits align with those established by Dantas et al. (Journal of South American Earth Sciences, 2023, 123, 104219), confirming the anisotropy and heterogeneity of the karst-fissured and fissured aquifers, and the isotropy and productivity of the alluvial aquifers. These findings provide crucial insights for managing aquifer reserves and mitigating water conflicts in the EPA region.