Multitechnical approach for the reconstruction of coastal changes: the case of Cala del Cefalo (southern Italy)

Coastal environments undergo continuous changes due to the complex interactions of geological, oceanographic, climatic, and anthropic processes. In the last centuries, human activities have deeply altered the natural balance of coastal areas, making coastal evolution studies crucial for planning strategies related to prevention, preservation, and restoration, particularly in areas with a relevant role in biodiversity conservation.
The aim of this research is the evaluation of recent morphological and environmental changes that occurred since the second half of the 20th century along the sandy stretch belonging to the Site of Community Importance (SCI) “Spiaggia del Mingardo e Scoglio di Cala del Cefalo” in the Campania region (Southern Italy), near the mouth of the Mingardo River. Through an integrated GIS analysis of topographic maps, aerial and satellite photos, and high-resolution data (a photogrammetric survey carried out with an aerial drone in April 2023), a retreating trend of both the shoreline and the dune system was observed. In particular, a decrease in the retreating trend of the shoreline has been detected since 2004, while the mean erosion rate is equal to -0.354m/y for the period between 2011 and2016, approximately 12 cm more than the previous time span. On the other hand, the retreat of the dune system over the whole period amounted to 40 m, 35 m, and 27 min the northern, middle, and southern areas respectively, while the highest retreat has been detected for the period between 2012-2016. This coincides with the results obtained for the shoreline between 2011 and 2016. Since one of the strongest storm surges occurred in 2014, this result demonstrates the great influence of storm surges on the state of conservation of the coast, as testified by detected wash-over fans and strong degradation of the vegetation cover. Therefore, the resulting forcing factors acting in the area are the winter wave regime, which can cause flooding and consequent dragging of sediment offshore, and the draining of the Mingardo River. Another relevant aspect is the intense anthropization of the area, especially during the summer season.
To conclude, this work provides evidence of the high impact of storm surges on beach and dune environments, showing the importance of an integrated approach for the analysis of coastal dynamics in a fast-evolving world, where human presence could strongly interfere with natural processes. The potential erosion risk is crucial information for sustainable management of the coast, also taking into account the expected increase in storm surge frequency and magnitude strictly related to climate change.