Hydrolithology of the area between Tuscany, Latium and Umbria regions (Italy)

Hydrogeological research lacks a standard methodology for supporting the management of groundwater resources in territory planning. The mapping of geological units in terms of their hydrogeological properties (such as permeability, effective infiltration, hydro-capacity) may provide a propaedeutical tool for calibration and validation of regional scale hydrogeological components (aquifer, aquiclude, aquitard). This work presents a hydrolithological map based on analysis of the 1:100,000 official cartography (provided by the Italian Geological Survey). The study area includes three distinct administrative regions (Tuscany, Latium and Umbria) and is a part of the central Apennines (Italy), an orogenic segment with distinctive tectono-stratigraphic sequences characterized by different degrees of permeability. A methodological approach is described that revises the geological information from the original cartography and builds a multicriteria database. The results are schematized in the attached map (at 1:100,000 scale) where the ‘hydrolithological complex’ (i.e. complex grouping lithologies with genetic and tectonic affinities and showing internal textural and compositional similarities that produce a comparable behaviour regarding groundwater flow and storage) is used as the key unit. Thematic maps illustrating permeability variation in the area and ‘macro-complexes’ are also included. The information is presented to outline the importance of revising, updating, and homogenizing geological cartography for providing direct multiscalar analysis suitable for territory planning.