Salinization factors affecting the coastal aquifers in eastern Sicily

Along the Ionic coast of Sicily, between Mt. Etna and Hyblean Plateau, the groundwater contained in the alluvial aquifers of the Simeto and San Leonardo river basins show variable salt contents and often remarkably elevates. The granulometric variability of alluvial deposits conditions the permeability, varying from average to low in the sandy-clay levels, high in the gravel and sand levels, reaching the lower values in the silty-clay levels. Such horizontal and vertical variability, in connection with the structural setting of the impermeable clayey basement, influences the flow of groundwater and the exchanges with the superficial environment, as the water chemistry records. The geophysical prospecting, stratigraphic data of wells and boreholes, water levels and chemical analysis correlation, has allowed to characterize the main origins of the salinity, while its evolutive trend since the last also 30 years has been carried out through the comparison with previous data. The intensive anthropogenic activity caused in time relevant consequences on the aquifers equilibrium increasing the groundwater salinization processes. These can result by different sources, such as fertilizer used in agriculture, industrial wastes and seawater intrusion caused by heavy groundwater extraction from aquifers.