A METHOD BASED ON BEACH PROFILE ANALYSIS FOR SHORELINE IDENTIFICATION

Coastal erosion coupled with human-induced pressure has severely affected the coastal areas of the Mediterranean region in the past and continues to do so with increasing intensity today. In this context, the Pisa coastal plain shows a long history of erosion, which started at the beginning of the nineteenth century. The work aims to provide a method and a software to extract the shoreline position. We apply the Structure from Motion (SfM) techniques to reconstruct a high-resolution Digital Elevation Model using a drone for image acquisition. The algorithm is based on the variation of the topographic beach profile caused by the transition from water to sand. The SfM technique is not efficient when applied to reflecting surfaces like sea water resulting in a very irregular profile over the sea. Taking advantage of this fact, the algorithm searches for the point in the space where a beach profile changes from irregular to regular, causing a transition from water to land. The algorithm is promoted by the release of a QGIS v3.x plugin uploaded on the official repository of the software, which allows the easy application and extraction of other shorelines.