Coastal risk along the North Adriatic Sea coast under Climate Change

On the 12th of November of 2019, flood levels in the Venice Lagoon have reached the mark of 1.87 metres, the second-highest level since records began in 1923. High tides and a storm surge driven by strong winds blowing north-eastwards across the Adriatic Sea contributed to the event. The combined effect of sea level rise and local land subsidence contribute to increasing frequency and intensity of extreme sea levels (ESL) in medium- to long-term. Upper-Adriatic Sea coast is vulnerable to coastal flooding, due to the morphological characteristic of the coast. In this paper we estimate the coastal flood risk using (i) ANUGA hydrodynamic and hydrostatic bathtub model, and (ii) damage and loss model framework estimating the tangible physical damage and induce macroeconomic effects on regional growth in three urban areas along the Upper Adriatic coast: Venice, Cesenatico, and Rimini. ANUGA is based on the Shallow Water Wave Equation discretised to unstructured triangular meshes using a finite-volumes numerical scheme (https://anuga.anu.edu.au). The models are forced by hydrodynamic sea level components (mean sea level, tides, storm surges and waves) driven from an ensemble of 6 climatic models (Vousdoukas et al., 2016). We compare the results of the models with existing hazard records and assessments. We apply a flood damage model developed for Italy to estimate the potential economic damages linked to the different flood scenarios, and we calculate the change in expected annual damages according to the relative extreme sea levels.