Monitoring and modelling interactions between the montagna dei fiori aquifer and the castellano stream (Central Apennines, Italy)

Groundwater is the most used water resource around the world, but due to population growth and climate change the alluvial lowland aquifers are often polluted and over-exploited. Thus, more and more frequently water managers need to shift their attention to mountain regions to identify groundwater resources for drinking purposes. This study presents a monitoring and modelling approach that allowed to quantify the inflow from the "Montagna dei Fiori" fractured aquifer to the Castellano stream. Continuous monitoring of flow discharge and temperature during an entire hydrological year (2018-2019) at two monitoring stations along the stream allowed to discriminate between the baseflow (on average, 0.891 m3/s) and the run-off (on average, 0.148 m3/s) components. A hydrogeological basin-wide numerical flow model (using MODFLOW-2005) was set up using information from hydrogeological and geomechanical surveys. The model was calibrated using the daily baseflow observations made in the Castellano stream (R2 = 0.75). The calibrated model allowed to quantify groundwater/surface water interactions. After an automated sensitivity analysis (using MODFLOW-2000), the recharge was found to be the most uncertain parameter, followed by the hydraulic conductivity zonation. This methodology could be applied in other mountain regions where groundwater monitoring networks are usually lacking to improve water resources management

Correction: Groundwater circulation and earthquake-related changes in hydrogeological karst environments: a case study of the Sibillini Mountains (central Italy) involving artificial tracers

The original version of this article was revised due to a retrospective Open Access order

Landfill Pollution Control with Isotope Techniques

IAEA-Conference Symposium Papers 23/

DOES THE RECHARGE AREA OF A SPRING VARY FROM YEAR TO YEAR? INFORMATION FROM THE WATER ISOTOPES

This study presents the characterization of the recharge zone and the water renewal mechanisms of the Gorgovivo spring, which feeds the aqueduct of the Ancona province and represents one of the most important water resources in central Italy. Measurements of chemical, isotopic and tritium contents were taken to get a detailed understanding of the hydrogeological setting and water circulation features. The isotopic investigation carried out in this study was performed thanks to the presence of different gauging stations for measuring rainfall heights and isotopic contents in precipitations, which allowed us to draw the altitude gradient that correlates the oxygen-18 content in groundwater with the isotopic height of infltration. This value changed over time (from -0.23‰ to -0.2‰/100 m) indicating the intake altitude for the Gorgovivo spring at a height ranging from 1030 to about 1200 m a.s.l. Tritium contents (about 8-13 TU for shallow springs present in the area, 6-8 TU for the Gorgovivo spring) and the different isotopic compositions confrm the supposed presence of a double pathway in the groundwater: the frst one being shallow and very ast - the small springs in the area studied belong to this pathway - while the second is slower and deeper, reaching the bottom part of the basal aquifer. The groundwater recharging the Gorgovivo spring is therefore a combination of these two pathways. Isotopic composition and tritium contents have also allowed the recharge area and recharge mechanisms of this spring to be investigated, by comparing the results with surface water and shallow spring waters. As a result, the present study introduces the likelihood of the recharge area of the Gorgovivo spring extending to more distant places in the Umbria-Marche ridge, thus confrming the suitability of isotopic techniques as a remarkable tool for recharge area evaluation

Quantifying streambed dispersion in an alluvial fan facing the northern italian apennines: Implications for groundwater management of vulnerable aquifers

Groundwater management of alluvial aquifers facing the northern Italian Apennines is an important issue that is becoming more complicated due to ongoing climate changes and increased water demands. The large groundwater withdrawals, coupled with an overall worsening of the water quality, require detailed knowledge of the recharge mechanisms of these aquifers that can be useful for further adaptation measures. We have focused our attention on a selected alluvial fan in which 49 slug injections of hyperconcentrated solutions of NaCl allowed river discharges to be estimated in seven different hydraulic sections. Consequently, losses from the streambed were assessed for the six river reaches along with the corresponding uncertainties in the estimates. The study confirms the suitability of such tests for identifying sectors in which streambed losses are promoted and for quantifying the total recharge conveyed to underlying aquifers. In addition, it has been demonstrated that the total streambed losses can be further linked to river discharges in any gauge upstream of the alluvial fan thanks to linear regression. Once obtained, the latter makes monitoring groundwater recharge by stream losses in real time possible if a permanent measurement device (such as the common telemetry used for river discharge monitoring) is available