Studio dell’interazione fiume-falda tramite modellazione numerica

The main aquifer of Ferrara province (Italy), the shallowest confined one in the multilayered system of the Po plain, is exploited by 3 well fields for human water supply, located near the Po river, in order to induce recharge from the river by the groundwater pumping. In the Guarda Ferrarese field an aquitard occurs between the riverbed and the aquifer and groundwatwer leakage through it has been studied through finite difference numerical modelling with MODFLOW. Calibration has been performed both at steady state (on 5 datasets), and at transient state (on a long-term aquifer test). Finally, a postaudit has been realized with one year of hydraulic head data at 3 multi-depth monitoring stations. The model has been useful for groundwater pumping management, but also for a better comprehension of the river-aquifer interaction. It also allows a quantitative evaluation of the “conductance” parameter and its influence on calibration process quality, model output and aquifer mass balance.