This contribute presents a detailed hydrogeological study of a Rome city sector, in the right bank of Tiber River, approximately inside the GRA highway and focused on the east of “Rio Magliana” stream.
A hydrogeological model of the subsoil of this city sector, more detailed than the most recent Hydrogeological Map of Rome (1:50.000 scale - La Vigna and Mazza, 2015) has been possible to obtain by means of the geologic-stratigraphical analysis, performed starting from the data provided by Environmental Protection Dep. of Roma Capitale (Municipality of Rome) and through the analysis of historical topographic and thematic maps of this sector. Moreover, the most superficial aquifer bodies have been identified.
The archived data have been elaborated by means of constructing detailed hydrogeological cross sections (1:10.000 scale). The water table contours’ elaboration was manually performed by means of triangulation methodology and then improved with visual methodology.
The obtained hydrogeological cross-sections highlighted that in the northern sector of the study area the upper volcanic deposits have an important thickness and base oneselves on a fine cineritic deposits called, on the geological map (Funiciello et al. 2008), “Tor de’ Cenci Unit”. Going towards the central and southern areas, the volcanic deposits thickness is reduced and the underlying "Ponte Galeria Formation" becomes more thick with the "Pisana Member", a stratigraphic member made up of three different lithofacies (Pgl 3a, Pgl3b, Pgl 3c). In the study area the “Sandy-clay lithofacies” (PGL3b) (Argille a Venerupis senescens Auctt.) presents a certain continuity. This stratigraphic setting also in conjunction with the water table available data and the springs’ elevations, allowed to suppose that the “Tor de Cenci Unit”, in the northern sector of the study area, and the “Sandy-clay lithofacies” of the “Pisana Member”, in the southern sector, can assume the role of aquicludes of their upper aquifers.
The hydrogeological conceptual model of the analysed sector allowed to detect the presence of two overlapping shallow aquifers bodies, the first in the upper volcanic deposits of Sabatini Mts, and the second in the most superficial sandy sediments of the “Ponte Galeria Formation” that sometimes can result confined.
Both circulations are separated from the underlying deeper regional aquifer, except for the sectors where the stratigraphic setting does not allow hydraulic separation and therefore determines a single groundwater circulation.
This hydrogeological setting has been represented in a detailed Hydrogeological Map 1:25.000 scale.
The detection of these shallow aquifers contributes to the basic knowledge for the protection of local water resources, especially from the anthropic pressure factors that insist on this area.