Dottorato in INGEGNERIA AMBIENTALE E IDRAULICA

Titolo della tesi: Karst-carbonate aquifer characterization by using innovative hydrogeological and geochemical methods

Water resources management is one of the most important challenges worldwide, because water represents a vital resource for sustaining life and environment. The continuous urbanization, and the improvement of the life quality, in many parts of the world, have led to an increasing demand for drinkable water. Water, even if it is, generally speaking, a renewable resource, is not available in the same amount anywhere and in anytime. The increasing demand for water, together with its variability, therefore leads to the "water crisis". The study and analysis of aquifers, and more specifically the study of innovative techniques and methods for the characterization of karst-carbonate aquifers, is a topic of great national and international interest. In this regard, the main objective of the European Union, with regard to water management, is to guarantee everyone access to good quality water, in sufficient quantity. Water resources of the karst aquifers contribute in some countries up to 50% to the supply of drinking water. Specifically, in Italy, karst carbonate aquifers of the central Apennines represent the largest groundwater reservoir. These aquifers are very complex systems, as each one has its own distinctive characteristics. They generally have great permeability, high speeds and large flows of water flows; these properties mean that such systems are very vulnerable and therefore need a careful and continuous qualitative and quantitative analysis. The peculiarities of karst aquifers make them strategic resources which, however, are not yet right exploitable, because of objective difficulties, that are found in their study. In this thesis, Capodacqua di Spigno Spring, one of the main groundwater outlet in the Southeast Latium Region, has been the test-site for the application of some innovative methods in karst aquifers investigation. The hydrogeological basin of this spring involves the competence territory of Spigno Saturnia, Formia and Esperia municipalities, in the province of Latina. Particularly, the present study focused on the Capodacqua di Spigno aquifer characterization by using two different approaches. The first topic dealt in this thesis concerns the evaluation of minimum karst spring discharge using two simple rainfall-input models. The second introduce a “Isotope Driven Model”, based on the relationship between δ18O and δ2H isotopes and the altitude infiltration, which lead to identify the involved recharge areas depending on different spring discharge values.