The availability of freshwater resources in mountain areas has been affected by climate change impacts on groundwater storage mechanisms. As a web of complex interactions characterizes climate systems, understanding how water storage conditions have changed in response to climate-driven factors in different Italian contexts is becoming increasingly crucial. In order to comprehend the relationship between changes in weather conditions and water availability in the Aosta Valley region and how their trends have changed over the last decade, a 7-year discharge series of different Aosta Valley springs (Promise, Alpe Perrot, Promiod, Cheserod) and precipitation data are analysed. Precipitation and flow rate trends using the Mann–Kendall and Sen’s slope trend detection tests were also performed. Not all of the Aosta Valley mountain springs detected seem to respond to the climate variation with a decrease in their stored water resources. Unlike Promiod, Alpe Perrot, Cheserod, and Promise springs have experienced an increase in water discharged amount during the detected 7-year period. This behavior occurs despite the available precipitation data for the associated Sant Vincent, Aymaville-Viayes, La Thuile-Villaret, Champdepraz meteorological stations revealing an overall decreasing trend in annual rainfall (mm), with a slight increase in intensity (mm/day) as a result of the reduction in rainfall events (number of rainy days).

Geological and geophysical exploration campaigns have ascertained the coexistence of low to medium-temperature geothermal energy resources in the deepest regions of Italian sedimentary basins. As such, energy production based on the exploitation of available geothermal resources associated with disused deep oil and gas wells in Italian oilfields could represent a considerable source of renewable energy. This study used information available on Italian hydrocarbon wells and on-field temperatures to apply a simplified closed-loop coaxial Wellbore Heat Exchanger (WBHE) model to three different hydrocarbon wells located in different Italian oilfields (Villafortuna-Trecate, Val d’Agri field, Gela fields). From this study, the authors have highlighted the differences in the quantity of potentially extracted thermal energy from different analysed wells. Considering the maximum extracted working fluid temperature of 100 °C and imagining a cascading exploitation mode of the heat accumulated, for Villafortuna 1 WBHE was it possible to hypothesise a multi-variant and comprehensive use of the resource. This could be done using existing infrastructure, available technologies, and current knowledge.

Thermal perturbation produced in the subsurface by open-loop groundwater heat pump systems (GWHPs) must be predicted and constantly controlled, especially in the shallow aquifers of more densely urbanized areas, in order to guarantee plants’ long-term sustainable use and to avoid adverse effects on adjacent geothermal systems. Transient conditions in the flow dynamic can be successfully modelled by means of numerical modelling tools. However, for small plants in suitable hydrogeological systems, an alternative tool for predicting the thermally affected zone (TAZ) around the injection well can be found in analytical solutions for steady advective transport in a shallow aquifer. The validity of using steady analytical solutions to predict the TAZ development at the end of two different cooling seasons (2010 and 2016) was tested in the Politecnico di Torino GWHP system (NW Italy). When fixing the constant thermal difference (ΔT) between the injection and abstraction wells at 5°C, results revealed that a rather reliable assessment of the TAZ of Politecnico di Torino GWHPs, in Turin shallow aquifer, can be performed by plotting the cumulative distribution function of the injected discharge rate (Q) and setting 63% as a steady value.

Mountain springs represent one of the largest and most precious sources of potable water in Italy, necessary to meet the water needs of the population. Optimizing the present and future management strategies of mountain groundwater resources has become increasingly necessary. The accuracy and frequency of the flow rate (Q) measurements determine and restrict the processes that can be studied using spring hydrograph and recession curve analysis. Therefore, to properly define mountain aquifers’ hydrogeological properties, it turns out important to highlight the variation of the error in the estimation of the hydrogeological parameters as the time interval of sampling varies. In this paper, recession curve analysis was performed on two different mountain springs (Spring 1 and Spring 2) of north-western Italy, firstly considering available 4-h resolution measuring data and subsequently by resampling data to simulate longer sampling intervals of 1, 3, 7, 15, and 30 days.The resulting distribution of errors introduced by longer acquisition intervals underlined how the percentage error increases with increasing acquisition interval. For obtaining an adequate estimation of mountain aquifer hydrodynamic parameters, in place of continuous hourly data, 1-day and 3-day sampling intervals with associated errors respectively lower than 5% and 10% were found to be valid.

For new buildings in densely urbanised cities, groundwater heat pump systems (GWHPs) represent a concrete, effective solution for decarbonising existing energy systems. Environmental factors must be considered to limit the GWHP system’s impact on the subsurface. Particular attention must be given to the long-term sustainability of groundwater abstraction modalities and the development of a thermally affected zone around re-injection wells. Simplified solutions and numerical models have been applied to predict subsurface heat transport mechanisms; these simulations allow researchers to consider site-specific geological conditions, transient heat and groundwater flow regimes, and anisotropies in the subsurface media. This paper presents a comprehensive overview of the current research on GWHPs and discusses the benefits and limitations of their diffusion in Italy. The sources used provide information on and examples of the correct methodological approaches for depicting the induced variations while avoiding the overestimation or underestimation of the impact that GWHPs have on exploited aquifers.