A coupled wave-hydrodynamical model to assess the effect of Mediterranean storms under climate change: The Calabaia case study

Abstract

Climate change will have an undeniable influence on coastal areas, resulting in increased rates of both sea level rise and storm-related impacts. In this context, it is crucial to estimate the local probable extreme sea wave conditions, to properly reproduce the sea state and the coastal hydrodynamic, and to investigate the effectiveness of sea defenses under sea level rise. This work describes the first steps towards an innovative fully coupled modeling system composed of a wind-sea wave (SWAN) and hydrodynamic model (2DEF). Numerical simulations, focusing on the shoreline of Calabaia, Cosenza, Italy, have been compared to the MIKE model outcomes in the same area. The simulations have been performed to investigate the inshore sea wave characteristics, to assess the effectiveness of the actual sea defense interventions, and to identify the impact of extreme storms, by combining sea level rise and extreme sea wave scenarios with the most recent georeferenced territorial data. The models are two-way coupled at half-hourly intervals exchanging the following fields: 2D sea level, surface currents and bottom elevation are transferred from 2DEF to SWAN; sea wave characteristics computed by SWAN is then passed to 2DEF by modifying the radiation stress.