Morphoevolutive drivers on a rapidly-evolving soft rocky cliff and connected shore platform system

Coastal zones, particularly rocky coasts, are increasingly shaped by extreme natural events and processes caused by human activities, making it essential to understand the key drivers guiding their evolution. This study examines the soft rocky coast and shore platform system of Tor Caldara Natural Reserve, a site of natural, archaeological and touristic significance. The research aims to identify the drivers that influence erosion, including lithology, rock mass properties, marine wave action, slope morphology and rainfall. A comprehensive approach combining traditional field surveys, multi-temporal Unmanned Aerial Vehicle (UAV) acquisition and multispectral analysis of high-resolution satellite imagery was employed to conduct a detailed analysis of geomorphic changes in the last 15 years. Marine and meteorological datasets were analysed to assess the impact of wave action and precipitation on coastal erosion. Wave height data were correlated and subjected to Peaks Over Threshold (POT) analysis to identify the peaks, corresponding to independent events, that could potentially impact the cliff. Rainfall data were also examined to evaluate whether precipitation intensity has played a significant role in accelerating cliff instability. The study reveals a dynamic and rapidly evolving coastal environment (in some local points about 1 m/yr of retreat of the cliff) characterized by both continuous and abrupt changes. Analysis of drivers controlling morphoevolution suggests that while marine and continental forcing play preparatory roles, the cliff setting, including lithology and structural conditions, is fundamental in driving coastal evolution at the study site. The evaluation of temporal mesoscale processes shaping the rocky coastline contributes to a better understanding of erosion processes affecting soft rocky coasts, serving as a basis of future research aimed at improving coastal management and risk mitigation strategies.