Coastal defence techniques and climate change: a review

Coastal areas are characterized by a high level of risk because of its intrinsic vulnerability to the sea action and the high number of socio-economic activities as well as of marine habitats. Traditional methodologies for the design of coastal defences cannot be applied straightforward in the presence of the effects of climate change because of the need to take into account the non-stationarity of natural processes. A novel approach based on an integrated coastal zone management is required to counteract the main consequences of global warming effects in coastal areas (i.e. sea level rise and the increase in frequency and magnitude of extreme events). In particular, besides institutional measures and preparedness and prevention actions, also structural intervention should be implemented. First of all, the upgrade of existing coastal defence structures should be considered, where this strategy is technically and economically feasible. In addition, it is suggested the realisation of Nature-Based Solutions, which consist on using natural processes to create a resilient system. Finally, the integration of traditional and innovative techniques for the design of coastal defences to realise resilient or, even better, antifragile systems is the most preferable approach. Indeed, perfect knowledge of future conditions is not needed for the design of antifragile systems, since this kind of structures are able to improve themselves when hit by unexpected events.