Characterization of extreme wave events at Cala Millor beach (Mallorca Island)

Abstract

[eng] Despite representing a small fraction of the land, coastal regions, vital for global socioeconomic activities, face inherent hazards from various physical forces, with scientific interest focusing on the dynamic responses of sandy coasts to wind-waves, due to their essential role as natural defences against flooding and erosion. Coastal hazards, such as sea-storms, result in coastal damage when the there is an overlapping between the area affected by storm-induced processes and intensive human use. Very often there is an absence of of systematic long-term data to evaluate the response of urban beaches to the wave storm processes, impact and recovery. But the SOCIB’s Beach Monitoring Facility in Cala Millor (Mallorca island, Western Mediterranean) provides valuable long-term waves and shoreline profile data, which, together with modelled wave data outputs by SCHISM model, lets us describe mean and extreme wave climate at this particular beach. Peak Over Threshold methodology is applied to define and detect extreme wave events. Using clustering techniques, wave and wind regional patterns associated with these extreme events are presented in terms of main variability and extreme regional patterns inducing coastal hazard and damage at the Cala Millor urban beach . Lastly, shoreline data, together with observed extreme events, are presented to better understand the impact of the events on the beach and the neighbouring human uses. The results show that there is no unequivocal response of the beach to the seastorm forcing. This response depends on the forcing, the magnitude and grouping of sea-storms, as well as, and on the beach initial state