Morphological changes of a Mediterranean beach over one year (San Giovanni Sinis, western Mediterranean)

Mediterranean beaches experience major modifications in their morphology and grain size features mainly during intense storms and extreme meteo-marine events. The assessment of beach response to storms can be useful in the evaluation of coastal hazards, and in relation to the efficiency of management projects such as artificial nourishment. This paper aims to establish the subaerial morphological response of a beach located in western Sardinia (western Mediterranean) during the period of a year. Both experimental and numerical approaches were adopted to investigate the beach system. In particular, beach profiles, acquired by means of Differential Positioning System were used to analyze the morphological changes of the beach and wave parameters and current velocity data were collected by means of an Acoustic wave and current meter (ADCP). Numerical techniques were also applied to investigate the hydrodynamics in the area of study. Coupled wind wave - 3D hydrodynamic finite element model were used to reproduce the wave propagation and the wind, tide and wave induced 3D water circulation along the coastal areas, and it displayed a good accuracy. During the year, the beach experienced intense morphological changes in the area where submerged beach is not occupied by rocky outcrops and the model was also able to reproduce the related observed periods of strong wind wave events. The interdisciplinary approach allowed an evaluation to be made about the response of the beach morphology in respect to meteo-marine forcings.