Modellazione numerica di flusso per la progettazione di un sistema di emungimento con pozzi a raggiera

In the city of Ferrara (Italy) water for human supply is mainly exploited from the Po River and only 1/7 of the total comes from groundwater of the first confined aquifer of the multilayered flow system of the Po plain. Problems related to low hydraulic levels in the river during dry season and to the high vulnerability of shallow waters to contaminant events, addressed the public authorities to evaluate and plan new exploiting strategies. The best solution is represented by two radial wells extending below the river, that allows to solve dryness problems and to lower the depuration costs taking advantage of the natural riverbank filtration. This strategy is here evaluated in relation to hydrogeological issues: a groundwater flow model has been developed with Feflow 5.3 in order to size the pumping rates and to predict the piezometric drawdown. Model has been set up collecting and organizing all the available data in the study area and particulary the detailed geological and hydrogeological data near the river in the supply area. Calibration has been performed both at steady state (with two different data-sets corresponding to 2003 and 2010) and at transient state (on 2 aquifer tests)