GIS-based hydrostratigraphic modeling of the city of Rome (Italy): analysis of the geometric relationships between a buried aquifer in the Tiber Valley and the confining hydrostratigraphic complexes

• Published in: Hydrogeology journal 2012-12, Vol.20 (8), p.1549-1567
• Main Authors: Di Salvo, C., Di Luzio, E., Mancini, M., Moscatelli, M., Capelli, G., Cavinato, G. P., Mazza, R.
• Format: Article
• Language: English
• Subjects: Alluvium; Aquatic Pollution; Aquifers; Earth and Environmental Science; Earth Sciences; Freshwater; Geographic information systems; Geology; Geophysics/Geodesy; Gravel; Groundwater; Holocene; Hydrogeology; Hydrology; Hydrology/Water Resources; Pleistocene; Pliocene; Quaternary; Recharge; Remote sensing; Satellite navigation systems; Stratigraphy; Three dimensional; Urban areas; Valleys; Volcanoes; Waste Water Technology; Water Management; Water Pollution Control; Water Quality/Water Pollution
• ISSN: 1431-2174; 1435-0157
• DOI: 10.1007/s10040-012-0899-2

A preliminary hydrostratigraphic model of the city of Rome (Italy) was completed through the analysis of geological and hydrogeological data, and by using geographic information system (GIS)-based operations. The complex lithostratigraphic setting of a local Quaternary volcano-sedimentary multilayer was simplified into hydrostratigraphic complexes considering textural properties of terrains and hydraulic conductivity values. The Tiber River Valley, in the middle of the urban area, was analyzed separately from the surrounding areas. GIS tools were used in a multiple-step procedure to reconstruct the geometry of bounding surfaces of the main hydrostratigraphic complexes. Particular care was given to the characterization of a confined gravelly aquifer lying at the base of the upper Pleistocene–Holocene alluvium that fills the Tiber Valley. Updated isobaths and thickness maps of this layer were produced. Three-dimensional reconstruction identifies areas of potential recharge between the alluvium aquifer and the surrounding hydrostratigraphic complexes. In the central sector of the city, the gravel deposits are laterally confined by a thick aquitard corresponding to the Pliocene clayey bedrock of the city; in contrast, a potential recharge area can be hypothesized in the northern areas, where the upper Pleistocene–Holocene valley cross cuts the Paleotiber Graben, filled with older and highly permeable gravels and clays.