Coastal restoration measures to mitigate coastal flooding in a context of climate change: the case of the South-East of Sicily

The South-East of Sicily is characterized by a complex system of coastal lagoons. The site, is considered of great naturalistic value, as it hosts a rich biodiversity and represents an important stop for bird species that migrates through the Northern European-African route. According to recent studies, the site is subject to an ever-increasing climate related coastal erosion and flooding risk, with an estimated potential land loss of 6.2 km2 by 2100 (Antonioli et al. 2020). In the present work, the effectiveness of a dune revegetation is investigated, in order to understand the role played by environmental restoration in reducing coastal risk. A SWAN+XBeach (Booji et al. 1996; Roelvink et al., 2009) numerical modeling chain is developed, aimed to simulating the hydraulic and transport processes that characterize a coastal area, in order to evaluate the effectiveness of the dune revegetation intervention. Results show a reduction of coastal flooding risk due to extreme wave events as an effect of the extended vegetated dune strip. Presence of the vegetation drastically improve coastal protection to the city area. Specifically, a reduction up to 42% of the flooded city area is observed. 

References 

Antonioli, F., Defalco, G., Moretti, L., Anzidei, M., Bonaldo, D., Carniel, S., ... & Schicchitano, G. (2019). Relative sea level rise and potential flooding risk for 2100 on 15 coastal plains of the Mediterranean Sea. In Geophysical Research Abstracts (Vol. 21). 

Booij, N., Holthuijsen, L.H. and R.C. Ris, 1996, The SWAN wave model for shallow water, Proc. 25th Int. Conf. Coastal Engng., Orlando, USA, Vol. 1, pp. 668-676. 

Roelvink, D., Reniers, A., van Dongeren, A., van Thiel de Vries, J., McCall, R., & Lescinski, J. , 2009. Modelling storm impacts on beaches, dunes and barrier islands. Coastal Engineering, 56(11-12), 1133-1152. doi:10.1016/j.coastaleng.2009.08.006