Evoluzione geochimica e modalità di gestione di un acquifero alluvionale

In the eastern hydrographic basin of the Po river, Northern Italy, the underground water circulation is strongly influenced by the recent geological and palaeogeographic evolution of the region, while the qualitative characteristics of the water are controlled by the depositional environment (continental, marine, etc.). Within such complex sedimentary environments, the exploitation mode plays a crucial role for the preservation of the overall aquifer quality. In order to evaluate the influence of the exploitation on the geochemical characteristics of the underground resources, hydrodynamic (piezometric level) and hydrochemical (Ph, temperature, electrical conducibility, content in HCO3, Ca, NH4, Fe, Mn, SO4, Cl, NO3, Cl, F and Br) data have been collected from the first unconfined aquifer and analysed. The investigated area corresponds to the territory surrounding Ferrara town. The elaboration of these data based on classical hydrogeological and hydrogeochemical methods, integrated with isotopic analyses allows a) to separate the principal hydrogeochemical facies, b) to recognise the occurrence of mixing phenomena between the water of the exploited aquifer and the salty water of the underlying aquifer, c) to infer about the equilibrium between the amount of pumping and the quality of the water.