Hydrogeological features of the Monteverde hill eastern slope (Rome urban area, Italy)

Abstract

The study area is located in the Monteverde Hill, urban area of the Rome City (Italy). Gravelly-sandy-silty geological formations outcrop in it. The aim of the present study was to outline the local groundwater circulation for contributing to accomplish a drainage system for preventing water infiltration in building basements. Local hydrogeological setting is very fragmented. The stratigraphical, hydrogeological, hydrochemical and piezometric data evidenced the presence of deep saturated sandy levels/lenses, saturated covering excavation soils and shallow mostly unsaturated gravelly/sandy horizons. The main recharge processes of groundwater-bearing bodies are due to direct infiltration from surrounding recharge areas and lateral drainage towards sandy lenses/levels. Two main sectors displaying different reference piezometric heads (about 47-55 in up-hill sector and 24-39 m a.s.l. in down-hill) were evidenced, due to presence of a soil retaining wall acting as a (semi)permeable divide in the middle of the study area. A further lower piezometric head interval (about 13-15 m a.s.l.) was at the base of the slope. All waters may be classified as bicarbonate waters. Strong or long-lasting rainfall did not evidently affected groundwater heads, likely because of diffuse cemented/asphalted paved surfaces. The hydrogeological budget evaluation of the study area suggested groundwater contributions from adjacent aquifers.