Morphodynamic evolution of Panxón beach (Galicia, NW of Spain)

Panxón beach (Pontevedra, NW of Spain) was quarterly surveying from November 2000 to January 2002. Five beach profiles were monitored and four sediment samples were collected in each profile that were located at the beach face and along the intertidal zone. This work presents Panxón beach behavior during the monitoring time and develops the foundations to a morphodynamical model of this beach. Seasonal variations of the beach respond to changes in wave climate: the slope of the measured profiles decreases and grain size increases during winter and storm conditions. In fair-weather conditions, the profile recovers sediment increasing its slope and building the berm of the profile. This seasonal behavior shows differential response along the beach: the zone protected by a headland at the north end of the beach and the zone exposed to waves, located at the south end. In the exposed zone, the slope variation range is related to the wave height changes. Morphology' of the exposed zone is conditioned by wave characteristics. In the protected area, wave height variation is minimum (0.2-0.4 m) during the monitoring period whereas slope profile changes is similar to the exposed profiles. Morphology of the protected profiles is defined by wave climate in summer conditions. During energetic conditions (winter and storm) it is made clear the existence of a different mechanism controlling the morphology in this zon