STORM-DRIVEN SHORE CHANGES OF A BEACH PROTECTED BY A LOW CRESTED STRUCTURE

The variability of a beach protected by low crested structures is examied in Lido di Dante, Italy. The beach shoreline and bathymetry is mapped with the aim of video derived survey, allowing the collection of 71 intertidal beach bathymetries in the period January 2004 - April 2007. In this way it was possible to study the shoreline variability immediately before and after single storm events. The beach evolution, described in terms of beach rotation, beach retreatment or accretion and sand volume transport, has been correlated to the wave energy flux in the nearshore. The rotation of the beaches is, as expected, strongly correlated with storm direction. During North storms we observe a high correlation between the total wave energy flux and the shoreline regression, after intense wave attack we observe the formation of sand bars in the swash zone.