Depositional environment of shallow-marine arenites in the Northern Apennines (Italy) affects aquifer performance: an interpretive key to groundwater management in a climate change scenario

Study Region: The Pantano Formation arenitic aquifer, in the Northern Apennine chain between Modena and Bologna (Italy). Study Focus: through an array of geological, hydrogeological and geochemical investigations across distinct members of the Miocene Pantano Formation, this study aims at assessing the influence of depositional environments on aquifer performance (i.e., recharge and storage capacity, spring discharge). As the investigated aquifer represents a key resource for drinking water in the Northern Apennines, interpreting depositional environments might drive future applications in areas understudied from a hydrogeological viewpoint. New Hydrological Insights for the Region: this study emphasizes the critical role of depositional environments in shaping the aquifer characteristics of the Pantano Formation. Sedimentary facies formed in relatively proximal environments, close to the paleo shoreline, exhibit higher bulk hydraulic conductivity, recharge potential, and storage than those formed in a more distal (open shelf) position, resulting in discharge through larger springs more resilient to droughts. These differences are attributed to depositional factors, such as textural heterogeneity and carbonate content facilitating karst dissolution. Moreover, numerical modeling indicated the feasibility of sustainable groundwater withdrawal though pumping, especially in nearshore sediments, offering a mitigation measure for future water supply challenges during droughts. Therefore, nearshore deposits cropping out in other sectors of the Northern Apennines hold a great potential to mitigate groundwater shortages during droughts and should be the object of further hydrogeological investigations.