BAYBEACH – Evolution and Management of Embayed Beaches in Contrasting Environments

SUMMARY

The need to improve the knowledge about the processes taking place in coastal areas, as well as to know the impact of human activities on the coast, have been recognized and assumed to be priorities on both national and international levels. This situation has led to an increased interest in the study of coastal dynamics and on improved knowledge about the geomorphological evolution of coastal areas.

BAYBEACH project aims to study the macroscale (decades) geomorphologic of embayed beaches and their interaction with the surrounding rocky cliffs, as well as to analyse the mesoscale (months to years) morphodynamic processes that drive embayed beach behaviour, in order to define the relationships that characterize the medium to long-term evolution of embayed beaches and understand the implications for coastal management. The macro and mesoscale approaches will be based in two geomorphological and morphodynamic contrasting coastal environments in south-western Portugal: the still pristine western coast, exposed to a very energetic wave regime, and the intensively occupied southern coast, relatively protected from the Atlantic swell.

Macroscale geomorphologic evolution studies are mainly supported by GIS based interpretation of multi-temporal aerial photography datasets on a decadal level. In terms of mesoscale analysis, six embayed beaches (Amoreira, Monte Clérigo, Arrifana, Salema, Boca do Rio and Cabanas Velhas) are the focus of regular topographic and sedimentary surveying, along with a reference bathymetric survey, in order to investigate the morphodynamic processes that drive the current morphological evolution of these six beaches. Three     new sites were included during the course of the project, Galé, Olhos de Água and Forte Novo, where detailed fieldwork aimed at understanding the interaction between rocky cliffs embayed beaches is being performed.

To support the geomorphological and morphodynamic analysis and aiming to develop a conceptual model of embayed beach behaviour, numerical models will be used as a tool to obtain insights about coastal circulation, sediment transport, definition of sediment cells, as well as classification of beach equilibrium state. Finally, in order to identify management options for embayed beaches, the main factors contributing to morphologic changes in embayed beaches and adjacent areas as a result of natural or human perturbations will be considered. This is expected to provide stakeholders and decision-makers with an integrated view of the medium to long-term evolutionary scenarios for the embayed beaches in the south-western and southern coasts of Portugal.