Groundwater level monitoring tests with seismic interferometry

The objective of this work is to evaluate whether the seismic passive interferometry technique can be used to monitor undeground water variations in both unconfined and confined aquifers that present different hydrogeological characteristics. We collected ambient vibrations in two different water catchment fields where the water level has been artificially modified by activating a pre-existing pumping system. We first estimated the seismic velocity variations by means of Stretching technique and then compared the obtained curve with the water table level monitored by the pumping system. For both the analysed case studies, the dV/V curves showed a clear correlation with the water table variations. Moreover, this experiment reveals that different time windows of the correlogram may infer a different composition of the seismic wavefield. Provided that the absolute groundwater depth can be retrieved, the ambient noise interferometry could be employed to develop a continuous water monitoring system with dense networks for better management of the water resource.