Tendenza evolutiva della spiaggia della Riserva Naturale della Sentina (San Benedetto del Tronto, AP)

Abstract The Regional Natural Reserve “Sentina” stretches itself for some 1.7 km along the southernmost end of the littoral area of San Benedetto del Tronto (AP) at the boundary with Abruzzo; it hosts one of the very few costal dunes still preserved in the Marche Region. Its gravelly-sandy beach in still natural, but is bound to the north by a long series of emerged barriers and to the south by a long (more than 300 m) pier; these structures noteworthy influence the retreat of the shoreline. In the area, a long monitoring (starting from 2000) has been carried out in order to interpret and quantify the modification occurred on both the emerged and submerged beach. During this time span, the shoreline retreated every year: up to 2006 its retreat has been evaluated in 27.7 m, with a local maximum of 33.5 m, whilst for the following 6 years (notwithstanding an artificial nourishment in 2008) it continued to retreat by 22.2, as an average. Therefore, in 12 years wave erosion resulted in some 50 m of backing; this also implied the loss of about 42’000 m2 of coastal dunes. Therefore, it is logical to assume that if no relevant intervention will be carried out, standing the almost absent nourishment deriving from the solid load of the Tronto R., in the next future the Sentina area will suffer progressive coastal erosion, with severe backing of the shoreline and distruction of the coastal dunes. Keywords: coastal erosion, monitoring, “Sentina” Reserve, coastal dunes