Coastal areas are among the most biologically productive, dynamic and valued ecosystems on Earth. They are subject to changes that greatly vary in scale, time and duration and to additional pressures resulting from anthropogenic activities. The aim of this work was to investigate the shoreline evolution and the main environmental changes of the coastal stretch between the towns of Licata and Gela (in the Gulf of Gela, Sicily, Italy). The methodology used in this work included the analysis of: (i) shoreline changes over the long- and medium-term periods (1955–2019 and 1989–2019, respectively), (ii) dune system fragmentation and (iii) the impact of coastal structures (harbours and breakwaters) on coastal evolution. The shoreline change analysis mainly showed a negative trend both over the long- and medium-term periods, with a maximum retreat of 3.87 m/year detected over the medium-term period down-drift of the Licata harbour. However, a few kilometres eastward from the harbour, significant accretion was registered where a set of breakwaters was emplaced. The Shoreline Change Envelope (SCE) showed that the main depositional phenomena occurred during the decade between 1955 and 1966, whereas progressive and constant erosion was observed between 1966 and 1989 in response to the increasing coastal armouring.

Coastal dynamic is the complex result of multiple natural and human processes, and past and future coastal behavior studies become fundamental to support coastal zone management. However, the reliability of coastal evolution studies is strongly dependent on the analyzed time interval. The longer the period is, the more reliable the past shoreline change analysis and the forecast of shoreline position will be. The present study showed the 50-years shoreline evolution of the Catania coastal plain (Southern Italy), a densely populated area where human-induced processes profoundly changed natural dynamics. Landsat and Sentinel imageries were used to extract shorelines’ position over the time between 1972 and 2022 and the DSAS tool was used to calculate the shoreline change rates. The shoreline evolution in 2032 and 2042 was performed by the Kalman filter method, a tool largely applied to forecast short-term shoreline future position. Most of the Catania coastal plain was mainly retreating over the last decades. However, the most significant changes were registered in correspondence with the coastal structures and the river deltas. The reliability of the forecasting model was highly related to the coastal morphology. As such, the lower RMSE values were calculated in correspondence with the uniform coastal subsectors.

Coastal depositional environments are the site of complex interactions between continental and marine processes. Barrier islands are highly dynamic coastal systems, typical of these transitional environments, and are affected by sea level changes and the accumulation of transgressive deposits with the landwards migration of the coast. The offshore of Marzamemi (Syracuse Province, Sicily), in the south-eastern portion of the Hyblean foreland, represents an excellent site for the study of transgressive deposits and their connection with the sea-level changes. The available dataset consisted of new high-resolution bathymetry (Multibeam), whose description and interpretation through a Digital Elevation Model (DEM) was integrated with a grid of eighteen seismic profiles (SPARKER). In the investigated bathymetric range, from about −5 m to −60 m, a sensibly different morphological setting between the northern and southern sectors was evident. Within the whole study area, three bathymetric contours (−45 m, −35 m and −20 m) were identified and assumed as the markers of the main locations of the paleo-coastlines during the recent changes in the sea level. Along the northern sector, three submerged barrier-lagoon systems developed on a calcarenite substratum, marking important steps of the Late Quaternary sea-level rise. They coexisted with numerous karst forms (poljes and dolines). In the southern sector the transgressive environmental evolution was significantly different and submerged lagoons did not form. Here the outcropping calcarenite substratum was affected by the development of paleo-rivers and karsts structures, a tract in common along with many Mediterranean carbonate coastal areas.

The assessment of the vulnerability of a site to tsunami events should take into consideration the geomorphological setting, which is strongly determined by the stratigraphic framework of the area. Lampedusa island is located in the central portion of the Sicilian Channel (Mediterranean Sea, Italy), where a significant incidence of tsunamis (with wave runup above 15 m) caused by earthquakes and submarine landslides has been historically documented. This work shows the geomorphological and stratigraphic differences between the western and south-eastern sectors of Lampedusa island. This update to the geological characterization of the island was used to create 3D flooding maps according to runup steps of 5 m, 10 m, and 15 m, thus showing a homogeneous involvement of the south-eastern sector of Lampedusa. Furthermore, our study aims to provide a geomorphological-stratigraphic base for a mathematical-statistical model to create coastal flooding maps due to tsunami waves. As such, this tool is useful for evaluation of strategic infrastructure for the security of the island and the improvement of risk management in civil protection.

The Mediterranean coastlines are densely populated zones which host key socio‐economic and commercial activities. For this reason, coastal areas are vulnerable sites in case of natural disasters as tsunamis that can strike coasts causing widespread damage to the population and facilities. For these reasons, several studies were performed over the last decade to study the impact of tsunami waves on the coasts. This research assessed the inundation risk due to a tsunami wave which can hit the southeastern coast of Lampedusa Island. The coastal low‐lying geomorphological setting of the southeastern part of the island led to significant socio‐economic growth, but Lampedusa falls within the Mediterranean Sea, a high‐tsunamigenic area, therefore, the need to investigate tsunami propagation and coastal flooding of this sensitive site emerged. For this scope, a calculation chain model was implemented incorporating three steps: the DELFT‐3D software for earthquake effects modelling, MIKE 21 Flow Model FM for nearshore propagation and HEC‐RAS for onshore tsunami inundation modelling. The simulations illustrate the impact of three tsunami scenarios with different magnitudes (M_w 8.5, 7.5, 6.5) generated by hypothetical earthquakes in the Hellenic Arc. In the M_w 8.5 magnitude scenario, significant flooding occurs in the harbour region, with maximum water depths reaching approximately 3.5 m. The maximum water velocity in this scenario reaches about 15 m/s in the eastern portion, adjacent to cliffs impacted by the tsunami wave. In contrast, the M_w 7.5 magnitude scenario demonstrates reduced flooded areas, with the cliffs containing the waves and preventing further flooding. Water depths and velocities in the M_w 7.5 scenario remain minimal. Changes in both propagation and flooding are not significant between scenarios M_w 7.5 and M_w 6.5. This methodology can be employed for more accurate tsunami wave simulations not only in the Mediterranean region but also in various case studies.