Avaliação histórica da ocorrência de ressacas marinhas e danos associados entre os anos de 1979 e 2013 no litoral do estado do Rio de Janeiro (Brasil)

Abstract

The paper presents a historical assessment of the occurrence of marine storms and associated damages in the coast of the state of Rio de Janeiro between 1979 and 2013. The wave characteristics associated to each event were analyzed to characterize the storm conditions that lead to damages on the beaches. Two case studies, one including the municipalities of Maricá and Saquarema, and the other at Macaé, were used to highlight the impacts of storms on urbanized beaches. Wave data between 1979 and 2013 for the coast of Rio de Janeiro were obtained through the wind reanalysis available from NOAA. The inventory record of damages associated with extreme sea conditions events on the coast of Rio de Janeiro was obtained from the database of the newspaper O Globo. The results showed 120 days between 1979 and 2013, with the occurrence of storm damages on beaches. The major number of storms occurred between May and September, when cold fronts are more frequent. Most data reported was associated to damage on streets, bars, boardwalks and houses built close to the coastline. Despite the more exposed coastal alignment to S wave energy, from Rio de Janeiro to Cabo Frio, the coastal sector located north of Cabo Frio is also associated to news of damage to structures on the coastal border. The analysis of wave height records relating to damage on the beaches showed an extensive range of heights, since less than 1 m to more than 4 m, from SE to SW directions. This result raises issues concerning the establishment of a wave height threshold “harm-inducing”. The case studies results revealed significant damages and losses related to the studied storms, pointing the importance of better understanding the behavior and the effects of these events regarding to a better management and planning of coastal areas.