Post-nourishment shoreline evolution of a partially protected beach

In this paper we describe the shoreline evolution of the Lido di Dante beach, Italy, over a 3.5 years period after a main nourishment intervention carried out in 2007. This coastal tract is partly protected by a system of low-crested structures and is partly natural (unprotected). A dataset of monthly-semimonthly surveys of the shoreline was generated by analyzing the ARGUS images taken through the video monitoring station in the period January 2007-December 2010. Wave and sea water level data were also collected for the post-nourishment period. The time series of Argus-derived shorelines showed the post-nourishment evolution of the intertidal beach and, particularly, pointed out the rapid evolution of the shoreline south of the groin system, where the beach is unprotected. Here the sediment was redistributed in a few months from the nourished area and partially transported downdrift, likely due to the occurrence of a number of storms from the NE (Bora winds). In the following years the shoreline returned more or less to the pre-nourishment position, showing natural (seasonal) fluctuations. In the protected beach, on the other side, the effects of the nourishment were reflected by an average shoreline advance of 10-20 m (with respect to the pre-nourishment position), which is still lasting in time. This was accompanied by local redistribution between and within the two main cells.