Morphodynamics of the Beach-Dune System of the Holocene Coastal Barrier of Siriu, Garopaba, SC

This paper presents a characterization of the Siriu coastal barrier (littoral of Santa Catarina state), in regard of its general formation process, and presents results of the study of the morphodynamic behavior of the beach-dune system of the barrier, aiming to determine the factors that controlled the formation of its transgressive dune field. Direct investigation methods (field work with sediment collection) and indirect (remote sensing, geographic positioning and georadar) were used, and a temporal series of winds was analyzed. The results showed that the barrier was formed, in part, by the progradation of a sandy spit. Simultaneously, a transgressive dune field was formed, with a direction of migration opposite to the development of the spit. The greater development of the dune field from the northern sector of the barrier is due to the greater availability of sand in this sector, a result of the dominant littoral drift towards the north, combined with the largest fetch of the dominant NNE wind. The main factors influencing the modern beach-dune system of the Siriu barrier correspond to the longitudinal variation in wave energy, the coastline orientation, the littoral drift, the morphodynamic beach state, and the direction and speed of winds.

Automated summary

This paper presents a characterization of the Siriu coastal barrier (littoral of Santa Catarina state) and its formation process. It also studies the morphodynamic behavior of the beach-dune system of the barrier and determines the factors that controlled the formation of its transgressive dune field. The results show that the barrier was formed by the progradation of a sandy spit and the formation of a transgressive dune field. The development of the dune field is influenced by factors such as wave energy, coastline orientation, littoral drift, beach state, and wind direction and speed.