Alongshore variations of beach configuration along the Tróia-Sines embayed coast (Southwest Portugal)

Abstract

Aerial photography of 1996 and 2001 coupled with DSAS extension for ArcGIS 9.x.The field data obtained by DGPS monitoring prototype system in 2009 were also to study the alongshore variations of beach configuration along 65km of the Tróia-Sines embayed coast (TSEC, SW Portugal). The results obtained show that the TSEC is characterized by the southward increase of the beach width, inner backshore height and seaward vegetation limit. The TSEC shows a southward increase of the beach width, inner backshore height and seaward vegetation limit allowing the definition of four main sectors. A singular increasing accretion tendency is observed at the northern extreme of the Tróia spit. The similarity between the alongshore shoreline beach width configuration does not reveal, at this scale of observation, the presence of the beach rotation phenomenon. The definition of the subaerial volume change seems to be more related with the variation of the subaerial inner backshore height rather than to the beach width.