"Estimation of groundwater volumes in the adda-oglio area (northern italy) by 3d reconstruction of hydrogeological properties"

The reconstruction and characterization of subsurface is a remarkable aspect in groundwater management, since a detailed reconstruction can highlight groundwater flow paths along the sedimentary bodies. In this paper, we would like to overcome the strong subdivision into aquifers and aquitards, introducing the concept of textural changing inside an aquifer. This concept is translated into a 3D reconstruction of textural and hydrogeological properties of the aquifers of the chosen study area, located between Adda, Oglio and Po rivers including Bergamo and Cremona Provinces (northern Italy). This hydrogeological reconstruction is used in order to estimate the volumes of gravitational groundwater located in the subsurface: the studied territory represents a very important area, considering the high groundwater consumption by drinking supply and anthropogenic activities. The area is composed of heterogeneous deposits shaped by both marine transgression phenomena and erosive processes carried out by rivers and glaciers. These deposits are classified into four different aquifer groups, called A, B, C and D (Regione Lombardia-ENI AGIP 2002) from the youngest to the oldest: aquifer group A is the shallowest and most exploited over the whole study area, whereas aquifers B, C and D are almost exclusively exploited in the North. The proposed procedure allows us to characterize the aquifer groups located within the study area, reconstructing the textural distribution and calculating the main hydrogeological properties. The parameterization of hydrogeological properties, such as effective porosity, allows us to estimate the potential quantity of water stored in subsurface deposits. This hydrogeological reconstruction will be followed by a flow model, currently under development, aiming to a better understanding of the hydrogeological dynamics within the study area.