Coastal impact of Mediterranean hurricanes in a future sea-level rise scenario

Coastal threats associated with Mediterranean cyclones (and the so called medicanes) and sea-level rise have become a significant concern over recent decades. These phenomena are affecting coastal communities, causing various issues related to coastal flooding. In this study, we modeled the impact of a Mediterranean hurricane under future sea-level rise scenarios along the southeastern coast of Sicily (Italy). The impact of Medicane Zorbas (September 26-29, 2018) was used as a baseline scenario for modeling the potential future effects of Mediterranean hurricanes. The significant wave heights and water levels were simulated using Delft3D, incorporating present-day conditions and sea-level rise scenarios for the years 2050, 2100, and 2150 under the IPCC 2021 projections. Coastal flooding, along with cumulative sedimentation and erosion, was subsequently modeled using XBeach in designated target areas previously affected by Medicane Zorbas. The model results were compared with observational tide gauge data to assess the root mean square error. Furthermore, morpho-topographic data acquired through Laser Scanner and Structure from Motion techniques were used to assess the morphological changes caused by Mediterranean hurricanes. The results of the model highlighted that flooding will increasingly affect larger areas in the near future. Additionally, a medicane event with an intensity 20% greater than Medicane Zorbas could impact larger areas at a mesoscale in the Mediterranean, with effects on beach erosion and deposit accumulation in the backdune areas.