Critical flood conditions in two beaches of the Portuguese central west coast

Abstract

Coastal flooding is expected to be one of the major impacts of climate change in the Portuguese continental territory. In this study beach morphological indicators and hydrodynamic forcings, assessed through field data, allow a comparative analysis of overtopping and flooding conditions in two beaches located in the Portuguese central west coast, Cova-Gala and São Pedro de Moel, during recent events. Results show that for the same hydrodynamic conditions beaches are differently affected. Water level and beach cross-shore profile gradient seem to be the main triggering factors for overtopping occurrence in Cova-Gala. In São Pedro de Moel beach, wave set-up and incoming wave direction can force inland inundation independently of the beach morphological state. These outcomes point out the importance of a comprehensive knowledge of the local factors in adequate flood hazard predictions and mitigation measures development.