Semi-empirical model of wave OVERtopping of seafront PROmenades with Emergent Toe (OVERPROET)

Coastal hazards are expected to increase as a result of climate change-induced sea-level rise and increased storminess. Given the complexity of the coastal environment and the changing wave forcing, it is imperative to deepen the understanding and improve the prediction of wave overtopping phenomena. Risky scenarios for assets and people who may be in exposed coastal areas during a storm must be avoided.

This project addresses the challenge of predicting the response of coastal seawalls in urban environments to extreme wave conditions under a range of future climate scenarios. The main objective is to achieve more accurate prediction models of wave overtopping of promenades, particularly for structures built on sandy beaches. These structures are located in areas that are very sensitive to sea level rise according to RCP scenarios. However, they were designed without considering the visible effects of climate change. 

Moreover, this type of structure operates in a system that is as variable as the existing beach profile, which is subject to regression and erosion and which, in the event of strong and prolonged storms, can accelerate and increase the frequency of the waves hitting the walls, to the detriment of their safety.

As a result, there is a threat to the integrity of these structures and to users and adjacent properties that needs to be carefully considered. Wave overtopping needs to be carefully assessed.

The project aims to provide a physically based model that fills the gaps between existing semi-empirical approaches. The research results will help to improve prediction models beyond the current state of the art, leading to a paradigm shift in the study of wave-structure interaction phenomena in urbanised coastal areas. 

To achieve its objectives, the project will combine large-scale experimental modelling with a combination of mobile bed (i.e. sand) and hard structures and advanced numerical modelling to collect and extend the existing international databases on wave overtopping and to develop new models for wave overtopping assessment of coastal structures on sandy beaches.