Assessment of groundwater resources resilience to future climate change impacts using a high-resolution aquifer model: the case of the Emilia-Romagna region in Italy

Aquifer depletion and over-exploitation of groundwater through increased pumping are well known global challenges. The impacts of these groundwater withdrawal on aquifer storage and groundwater recharge need to be carefully studied to assess their effect on groundwater conditions in regions where extensive groundwater withdrawals occur. The Emilia-Romagna region in Italy is an excellent case of a highly monitored aquifer system playing an essential role for water supply for civil, agricultural, and industrial use. A large agricultural plain is located in this area, and its subsurface consists of multiple aquifers at different depths in fluvial sediment deposits of several hundred meters thickness in total, underlaid by marine sediment deposits. Large amount of detailed information on aquifer characteristics, water withdrawals, and water table levels is available and enables the calibration of a high-resolution dynamic three-dimensional groundwater model. The MODFLOW 6 numerical code is used in our study to build the aforementioned groundwater model. This model is based on a previous application of MODFLOW to the whole Emilia-Romagna area by the Regional Agency for Environmental Protection (ARPAE), and extends over a wide area east of the Secchia River. Our MODFLOW 6 groundwater model provides satisfactory performances, based on validation with piezometric levels over a time span of 17 years.

Banking on the above detailed groundwater model results and performance, we analyse aquifer resilience to climate change and groundwater withdrawals, by running simulations with assigned perturbations of the current input data. We also analyse the future state of groundwater levels according to predictions provided by global climate models. The aim is to get an insight of the combined effects of changes in natural and artificial stresses on groundwater levels in the Emilia-Romagna region. This, in turn, would provide a guideline for sustainable aquifer management under different climatic conditions improve the resilience of regional aquifers.