Coastal Impacts Induced by Storm Waves between Cape Frio and Cape Buzios, Rio de Janeiro, Brazil.

The wave field in deep waters is notable for its variability and dictates the energy that will be directed towards the coast. Morphological impacts on coastal environments depend on the magnitude of the meteorological and oceanographic forcings and the beach capabilities of absorbing this energy. In the analysis between Cabo Frio and Cape Buzios, we considered the textural characteristics of the inner continental shelf from the analysis of 394 sediment samples, the volumetric variability of 438 surveys along 17 beach profiles and characteristics of 75 storms between 2003 and 2014. Results showed that sedimentation in the nearshore, through the mean grain size parameter, reflects the areas with higher or lower wave energy. The results also indicated the occurrence of a "storm waves season" between April and September, and this is the main element associated with erosion and volume variation of subaerial sand stock on beaches. A period with no occurrence of these storm waves (extended summer season) lead to the recovery of this subaereal sandy stock. The different segments of beaches show the greater or lesser magnitude of these effects, depending primarily on the orientation and exposure of each beach segment and also beach morphodynamics. Isolated storms with greater magnitude tend to promote severe erosion, especially if they occur at the beginning of this "season of storm waves".