Characterisation of shallow aquifers by 2D high-resolution seismic data analysis

We present the results obtained processing high-resolution seismic data acquired along the resurgence line located in the Friuli-Venezia Giulia plain (NE Italy), in order to characterize an important multilayered aquifer. This system is made up of an unconfined layer and, at increasing depths, of several confined aquifers of variable thickness and hydraulic permeability, mainly consisting of sandy/gravelly material. The main targets of this study are two shallow aquifers located at a depth of about 30 m and 180 m, respectively. The velocity model obtained reveals lateral velocity variations with a maximum value of 600 m/s. The higher velocities could be associated with layers constituting confined aquifers. Pre-stack depth migration using the above velocity model gives a clear picture of the multilayered aquifer, highlighting lateral changes in reflectivity.