MONITORING THE PHENOMENON OF SEAWATER INTRUSION IN THE ESTUARY AREA OF THE RIVER MAGRA AND IN THE ALLUVIAL PLAIN OF THE LOWER VAL DI MAGRA (SP)

Seawater Intrusion (SI) is a critical problem as a consequence of climate change. The progression of the salt wedge inland compromises the quality and quantity of groundwater, seriously damaging agriculture and gradually desertifying the territory. The alluvial aquifer of the Lower Val Magra (LVM) is one of the most important in Liguria (Italy). It supplies drinking water to the city of La Spezia. The main objective of this research is to determine the severity of the SI phenomenon in the LVM aquifer and in the River Magra estuary. Data from different databases (ACAM, Aral, Ispra) and new original data were used for this purpose. The analytical methods focused on multivariate statistics (HAC, PCA and PLS). It was found that the migration pattern of SI along the estuary is mainly controlled by river discharge and wind speed. The weir in Romito (8.5 km from the sea coast) is the current limit of the SI in the R. Magra. About the groundwater, the most salinized wells are concentrated in the Marinella plain. For the other part of the LVM, aquifer water quality is good, but will be deteriorate in the next years as a consequence of climate change.