The Italian Coasts: A Natural Laboratory for the Quality Evaluation of Beach Replenishments

BARSANTI, M., CALDA, N and VALLONI, R., 2011. The Italian Coasts: a Natural Laboratory for the Quality Evaluation of Beach Replenishments. In: Micallef, A. (ed.), MCRR3-2010 Conference Proceedings, Journal of Coastal Research, Special Issue, No. 61, pp. 1–07. Grosseto, Tuscany, Italy, ISSN 0749-0208. The present paper describes the joint research recently carried out by the University of Parma and the ENEA Marine Research Centre of La Spezia for the characterization of grain-size and petrography of the Native sediments of the Italian marine coastal territory. The work aims to establish a protocol for the evaluation of the “quality’ of artificial beach replenishment fills. GIS technologies have been used to create a national database on coastal cells. The Italian territory is composed of 188 Littoral Cells if coastal stretches less than 5 km long are ignored. On these Cells over two hundred sample couples of dune and beach sediment were collected and analysed for grain-size and thin-section petrography. The original petrographic classification adopted here is also suitable to the collection of literature data and is based on four fundamental sediment sources named Terrigenous silicate, Terrigenous carbonate, Indigenous and Pyroclastic, that may expand into eight petrographic compositions depending on the prevailing grain type: Quartzitic, Feldspathic, Metamorphilithic, Volcanilithic, Dololithic, Calcilithic, Bioclastic and Tuffitic. The foreshore sands reach their maximum diameters in Sardinia and Sicily where the Median (D50) ranges 0.801.50 phi (medium and coarse sands, with D50 averaging 0.50 mm). The foreshore sands show their minimum diameters in the Adriatic coast where the Median ranges 2.0–3.0 phi. These grain-size trends are also reflected in the dune sands that reach their maximum values in Sardinia where D50 ranges 1.00–2.50 phi. Beach-dune sample couplets indicate that the sediment textural maturation is poorly effective in the Adriatic coasts and highly effective in the Tyrrhenian coasts.