Coastal Risk Management in Europe: Methods and preliminary results of the CoCliCo Project

Coastal flooding, both current and future, is a significant concern for Europe due to sea level rise, storms, and the exposure of critical infrastructure in low-lying coastal zones. To support adaptation efforts, it is essential to have information on future risks, including people and infrastructure at risks and potential economic damages. One of the objectives of the CoCliCo project is to address this need by providing new coastal risks assessments in Europe using state of the art coastal hazard, exposure and vulnerability datasets and information, including dynamic flood hazard assessment and new maps of infrastructures at risk.

This study first presents the risk assessment methodology used for the CoCliCo platform, which is divided into two parts. The first part focuses on physical risks, evaluating the number and area of infrastructure exposed to coastal flooding, as well as the potential costs of these damages. Cost calculations are based on vulnerability curves that take water depths into account, to accurately estimate damage for each infrastructure type. The second part concerns the assessment of the number of people exposed to coastal flooding, based on downscaled demographic projections. This study is conducted at the European scale, using simulations of coastal flooding for events with annual, centennial and millenial return periods, at various time points and under different socio-economic scenarios.

Preliminary results indicate that e.g. around 200,000 persons and 1.2 Billion euros are exposed to centennial flood events along the coasts of Europe (preliminary results based on the analysis of around 60% of the European coastal flood plains). In a virtual scenario in which current coastal protection would be suddenly removed, these figures increase by a factor of 50 to 100. Without further adaptation, people exposed to a centennial storm are projected to increase by 400% in 2050 while assets at risks increase by about 250%. Beyond 2050, results depend on future land use planning decisions and relocations within and outside the low elevation coastal zone. Despite their uncertainties due to e.g. the 25m resolution digital elevation model used to perform coastal flood simulations and the lack of precise and site specific information on coastal protection, these preliminary results remind the benefits of adaptation, the importance of maintaining current defenses to prevent large disasters and the need for further coastal adaptation decisions (including protection, accommodation and relocation, including with nature based solutions) in the coming years and decades. The results will be made available on the CoCliCo platform.