EXPLORING THE INFLUENCE OF SEAFRONT LAYOUT AND WATER LEVEL ON EXTREME OVERTOPPING EVENTS: A STUDY BASED ON FOCUSED WAVE GROUPS

Assessing wave overtopping for coastal defense design is crucial, as it is vital for the evaluation of flood protections and essential to safety and risk mitigation. There is a debate about whether the average overtopping or the largest waves, which can cause the most damage, should be the primary design criterion. The EurOtop manual (2018) provides guidance, suggesting adaptability based on specific conditions and site use. The proposed study implements focused wave groups in an experimental flume facility aiming to investigate the variability of maximum individual overtopping volumes at sea dikes with shallow water conditions and/or emergent toes. By employing focused wave groups, it is crucial to comprehend how the combination of focus phase, focus location, water levels, and sea front characteristics are affecting the measured volumes and represent a sea state storm. The ultimate objective is to achieve a parametric optimization of focused wave groups for laboratory practices and analyses of extreme overtopping events at coastal defenses. Here, we compare two different foreshore slopes and four different sea dike slopes, in combination with varying water levels and three different wave conditions, to provide a preliminary comparison of all cases. This will pave the way for further parametrization of the focused wave groups technique applied to model extreme overtopping events.