Saltwater intrusion in the Muravera plain (Italy)

The Muravera plain is located in the South-Eastern part of Sardinia, Italy's second largest island, at the mouth of the Flumendosa river, and covers an extension of about 130 km2. The three main centers of the plain (Muravera, Villaputzu and San Vito) comprise a population of circa 13000. The main economic activities in this area are farming, citrus fruit growing, sheep and goat grazing, and tourism. Climate is Mediterranean subtropical, characterized by a strongly variable rainfall regime with annual precipitation fluctuating between 200 and 700 mm. Saltwater encroachment in the coastal aquifer and salinization of the soils was first observed in the 1970s, attributed to a lowering of the groundwater table due to both natural (recurrent droughts, presence of salty geological formations) and anthropic factors, such as overpumping, engineering works, and fish-farming. Currently both the phreatic and confined aquifers are contaminated with saltwater. Remedial measures being considered by the Ente Autonomo del Flumendosa (EAF), one of the subjects responsable for the management of water resources in the area, include artificial groundwater recharge, creation of hydrodynamic barriers, and establishment of a district irrigation network. In order to improve the understanding of the dynamics of the degradation of the aquifer and to support these remediation strategies, a research study for the simulation of the saltwater intrusion process by means of physical- mathematical flow and transport model is necessary. This study is being undertaken within an international cooperation project including research work from similar studies which are being (or have been) undertaken at two other sites in Tunisia and Morocco (Paniconi, 2000). Prior to initiating the simulations, the work undertaken has consisted in an integrated overview of diverse types of data made available by EAF. The scope of this evaluation was to assess the quality and quantity of the information, with respect to the data requirements both for an integrated GIS-based characterization of the site and for the simulation model.