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Core data from five boreholes drilled in 2017 in the Colosseum hypogea are of great interest for defining the Middle Pleistocene fluvial paleogeography and paleoenvironment in the Roman Basin. A detailed facies analysis and lithostratigraphic correlation with numerous other core and outcrop data from nearby areas, including the Palatine, Roman Forum, and Capitoline Hill, were performed in order to precisely reconstruct the subsoil of the monument and of the wider archaeological area. Two well-defined paleovalley infills have been identified, whose formation was linked to sea-level changes correlated to MIS 12-11 and MIS 5d-1 and associated with the ancient Tiber River and the recent Fosso Labicano stream, respectively. The Middle Pleistocene paleovalley stretches in the N-S direction, reaching a width of up to 500 m. It was extensively carved during MIS 12 into older volcano-sedimentary interfluves (MIS 16-13) and the Pliocene substratum. The valley infill is 40 m thick and corresponds to the Fosso del Torrino formation, deposited during the MIS 12-11 transition. This formation comprises basal gravels that grade upward to cross-bedded channelized sandstone, which contains remains of vertebrates such as Palaeoloxodon antiquus and Bos primigenius. Additionally, the formation includes floodplain clays and silt with interbedded lignite seams and tephra. The western side of the Colosseum is founded on pebbles and sands of an eastward-directed concave side of the paleovalley, while floodplain and marshy deposits are found further west beneath the Palatine hill, on the convex bank of the ancient river. The paleovalley trunk of the historical centre of Rome correlates well with the downstream fluvial sandstones cropping out at the fossiliferous site of Via Ostiense in the Colli di San Paolo area, where lateral input from an ancient left bank tributary is inferred., Journal of Mediterranean Earth Sciences, Vol. 15 (2023): In progress

The study of aquifer systems from a quantitative point of view is fundamental for adopting water management plans aiming at preserving water resources and reducing environmental risks related to groundwater level and discharge changes. This is also what the European Union Water Framework Directive (WFD, 2000/60/EC) states, holding the development of numerical models as a key aspect for groundwater management. The objective of this research is to i) define a methodology for modeling a complex hydrogeological structure in a structurally folded carbonate area and ii) estimate the concurrent effects of exploitation and climate changes on groundwater availability through the implementation of a 3D groundwater flow model. This study concerns the Monte Coscerno karst aquifer located in the Apennine chain in Central Italy in the Nera River Valley.This aquifer, is planned to be exploited in the near future for water supply. Negative trends of precipitation in Central Italy have been reported in relation to global climate changes, which are expected to affect the availability of recharge to carbonate aquifers throughout the region . A great concern is the combined impact of climate change and groundwater exploitation, hence scenarios are needed taking into account the effect of possible temperature and precipitation trends on recharge rates. Following a previous experience with model conceptualization and long-term simulation of groundwater flow, an integrated three-dimensional groundwater model has been developed for the Monte Coscerno aquifer. In a previous paper (Preziosi et al 2014) the spatial distribution of recharge to this aquifer was estimated through the Thornthwaite Mather model at a daily time step using as inputs past precipitation and temperature values (1951-2013) as well as soil and landscape properties. In this paper the numerical model development is described. On the basis of well logs from private consulting companies and literature cross sections the multilayer aquifer was conceptualized as five folded hydrostratigraphic units: three main carbonate aquifers are separated by two aquitards, which can be locally discontinuous, leading to a complicated flow pattern. In general the vertical leakance is upward from the basal aquifer to the unconfined uppermost aquifer. As shown by the increasing discharge from north to south, the Nera river acts as the main sink of the study area, gaining groundwater as it cuts through the folded terrain. The numerical model was implemented using the MODFLOW-2000 code and extends over an area of 235 km2 with a grid spacing of 100 meters in each of the 5 layers. Model calibration was achieved by comparing the model results with observed streamflow of the Nera river (8-10 measures per year during 1991-1993 and 1996-2012) which on the basis of the river hydrograph at gaging locations is considered to be derived entirely from groundwater. The effects of climate variation on groundwater discharge to the river in the past 60 years

A seismic sequence in central Italy from August 2016 to January 2017 affected groundwater dynamics in fractured carbonate aquifers. Changes in spring discharge, water-table position, and streamflow were recorded for several months following nine Mw 5.0–6.5 seismic events. Data from 22 measurement sites, located within 100 km of the epicentral zones, were analyzed. The intensity of the induced changes were correlated with seismic magnitude and distance to epicenters. The additional post-seismic discharge from rivers and springs was found to be higher than 9 m3/s, totaling more than 0.1 km3 of groundwater release over 6 months. This huge and unexpected contribution increased streamflow in narrow mountainous valleys to previously unmeasured peak values. Analogously to the L’Aquila 2009 post-earthquake phenomenon, these hydrogeological changes might reflect an increase of bulk hydraulic conductivity at the aquifer scale, which would increase hydraulic heads in the discharge zones and lower them in some recharge areas. The observed changes may also be partly due to other mechanisms, such as shaking and/or squeezing effects related to intense subsidence in the core of the affected area, where effects had maximum extent, or breaching of hydraulic barriers.