Quick analysis of the characteristic hydrogeological parameters of an aquifer, using empirical formulas and the implementation of the clay substrate map: the case study of the shallow aquifer of the S. Eufemia Lamezia plain (Central Calabria - Italy).

Abstract

In Calabria, there are few works of quantitative hydrogeology. Therefore, the present study aims to provide a contribution to the hydrogeological knowledge of the region and, in particular, of the shallow aquifer of the S. E. Lamezia plain, characterized by a multi-layer aquifer. The study area is located in the Tyrrhenian sector of the “Graben of Catanzaro, an important tectonic structure in the wider context of the Calabrian Peloritano Arc. The acquisition of new lithostratigraphic and hydrogeological data, related to drillings for water research, has allowed expanding the knowledge of the phreatic aquifer of S. E. Lamezia plain. In the study area, there is a high number of abusive wells without data, not declared and are made without a basic hydrogeological study. Therefore, they are free of flow rate tests and information about the drilling depth, stratigraphy and construction methods. However, a certain numbers of wells is authorized and the available data are: Stratigraphy, static and dynamic level, critical flow rare (Qc) and, in some cases, also the specific lowering (Δs). Therefore with these data, using empirical formulas, a quick analysis of the hydrogeological parameters characteristic of the aquifer it was done. Moreover, interpolating the stratigraphic data with a geostatistic method the map of the clay substrate was returned. In particular, the Transmissivity [T] and the Storage coefficient [S] were calculate with empirical formulas using well data. From the Transmissivity. the Hydraulic conductivity [K] is derived. The hydraulic gradient from the piezometric map graphically is calculated. The thickness of the saturated layer (b) of the aquifer was obtained directly from the stratigraphy of the wells surveyed or, in those cases in which stratigraphy was not known, from the differences between the values obtained from the isopiezometric map and the map of the clay substrate. In conclusion, this study, with the implementation of the clay substrate map and a quick analysis of the main hydrodynamic parameters, aims to provide a contribution to the definition of the hydrogeological model of the shallow aquifer of the Plain that represents a fundamental tool for the protection and the correct management of the water resource.