Effects of climate change on groundwater feeding the Mazzoccolo and Capodacqua di Spigno Springs (Central Italy): First quantitative assestments

In Italy, the summer of 2017 was characterized by serious problems related to the water crisis that affected the entire national territory. The Municipality of Formia, as well as many other territories in the Latina Province, had to face heavy rationing of the water supply during the summer, with consequent inconvenience for the population. In this paper, two spring and their relative aquifers were studied: the Mazzoccolo Spring and the Capodacqua di Spigno Spring. For both aquifers, a hydrogeological water balance was calculated based on the collection of thermo-pluviometric data on an appropriate time series, at the meteorological stations present within and around the study area. The main goal was to establish, in the context of current climate change, the potential of the aquifers that feed these water resources. For the calculation of the active recharge, in order to have an estimation value of the supply volumes, data referred to four meteorological stations in the study area for a time series of 40 years (1959-1999) were collected and processed. The stations considered are the following: Gaeta, Itri, Esperia and SS Cosma e Damiano pluviometric stations. Each basin has been divided into finished square elements (FSE), with a size of 10000 m2, using a GIS software. The value of the effective infiltration to assign to each cell is a function of the annual rainfall value and the annual evapotranspiration value, both referred to the cell itself. The sum of all the values referred to each cell of the grid, provided the estimation of the aquifer annual average recharge as average annual volume. The same procedure was used for maximum, minimum and medium values of the rainfall on the time series considered and for the single annual rainfall value of 2017. Results confirmed the extraordinary nature of the drought event that occurred during the recharge period of 2017, showing a huge decrease of the average available water volume. In conclusion, for the Mazzoccolo and Capodacqua di Spigno Springs, future interventions are going to be planned for the catchment optimization in order to overcome any future possible water crises, even considering the permanent reserves, without compromising their medium and long term availability and their quality.