Nearshore Morphological Change Assessment of the Beach of San Montano, Ischia (Italy): Beach Nourishment Implications

The current study seeks to improve beach nourishment operations by proposing a methodological monitoring approach aiming at identifying and excavating the sediment needed for such operations. Here, we propose the nearshore morphological change assessment approach as a tool for the coastal monitoring and protection remediations. Such a tool would help policy makers and scientists working to find solutions and mitigate the impacts of climate in coastal and low-lying areas. This study was conducted on the beach of San Montano located on the Island of Ischia in the Gulf of Naples; this area has been subject to processes of erosion and accretion recorded for the last 50 years. In addition, meteo-marine events observed in this area have increased coastal erosion processes. However, given the fact that this area is a naturally semi-protected beach, previous studies have indicated that the natural and anthropological events did contribute to the total loss of sediments far from the shoreline. In this case, morphological and hydrodynamic analyses would help to monitor and reuse the sediment involved in nourishment processes. Four topo-bathymetry surveys were conducted using a single-beam echosounder and GPS; in addition bottom sea current measurements were conducted to evaluate morphological variations of the submerged and emerged beaches. The results indicate that the sediments have been deposited in the shallow water of about 4 to 6 meters. In addition, the results obtained from the analyses of the direction and the velocity of the bottom sea current indicate that the distribution of the sediments used for the beach nourishment can be estimated with high precision. The overall results indicate that the proposed monitoring methodological approach would be a resilient and cost-effective strategy for the mitigation of the impact of coastal erosion.