Geomatics Workbooks n° 12 – "FOSS4G Europe Como 2015" Deinition of hydrogeological tectonic blocks into Guarani/Serra Geral Integrated Aquifer System using QGIS Leônidas Luiz Volcato Descovi Filho 1 , Arthur Schmidt Nanni 1 , Luiz Fernando Scheibe 1,2 1 Universidade Federal de Santa Catarina, UFSC, Brazil 2 Conselho Nacional de Desenvolvimento Cientíico e Tecnológico, CNPq, Brazil Abstract The application refers to the Guarani/Serra Geral Integrated Aquifer System (SAIG/SG) in Santa Catarina State, Brazil. Based on Digital Elevation Model SRTM and derivatives, large features relecting hydrogeological tectonic blocks 1 were deined. The interpretation of diagnostic proiles diferent scales result hydrogeological tectonic blocks. With hydrogeological database, calculate the hydrogeological tectonic blocks mean surface. Using QGIS Free Geographic Information System in this study was highly feasible. Keywords Geomorphostructures, QGIS, Terrain Proile. 1 Introduction Serra Geral, Botucatu and Pirambóia formations constitute a major aquifer system in Southern Brazil’s Paraná Sedimentary Geological Basin, the “Guarani/Serra Geral Integrated Aquifer System” (SAIG/SG). The Serra Geral Formation is a fractured volcanic reservoir that override the Guarani Aquifer System, a porous ine to middle grain sands aquifer type. Cutting both geological units, there are a lot of fractures and normal faults that connect these aquifers, allowing descendant or ascendant low, with the exchange of diferent water types (Scheibe and Hirata, 2008). The major objective of this research is the deinition of the hydrogeological tectonic blocks that make up the spatial arrangement of these two aquifers, that should be exploited as a single integrated system, in southern Brazil. The determination of these blocks is being held through QGIS and its native tools and plugins. These tools combined with a new hydrogeological database, provide support for the determination of the elevation of each tectonic block that deine hydrogeological tectonic blocks, allowing to deine vertical displacements and enabling to determine edge disconnections between the geologic strata layers. To improve the technical knowledge of SAIG/SG in Santa Catarina state, this study sought support in geotechnology tools, specially the QGIS, 2.6.1 Brigthon 1 delimited blocks from erosional features and structures, indicated by simultaneous viewing, using transparency of layers slope, hypsometry, shaded relief and drainage network, with tectonic and hydrogeological signiicance. 455