Migração lateral da desembocadura do Rio Itapocú, Santa Catarina - Brasil: evolução morfológica e condicionantes físicas / Lateral migratin of the Itapocú Inlt, SC -Brazil: morphological evolution and forcing conditions

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Inlets are highly dynamic environments subjected to the complex interaction between stabilizing and destabilizing factors. Depending on this interaction, inlets have a tendency to migrate along sandy barriers. One of the most effective mechanisms for transporting sediment alongshore and consequently controlling the migration of inlets, are currents generated by waves approaching the coast at an angle. The motivation of this study is to better understand the morphodynamic behavior of the Itapocú inlet, at the northern Santa Catarina coast. The morphology of the sandy spits that enclose the inlet was obtained from morphological surveys conducted with the use of DGPS. To analyze the wave refraction the numerical model MIKE 21 SW has been applied to the region. Boundary conditions have been set based on a one-year long database (2002) and predicted waves for the studied period. The model output has been used to estimate the potential longshore drift in the region. Results show the migration of the inlet to the north during the analyzed period, with higher migration rates during winter and summer. Waves inciding from the south are the most influenced by the refraction process, while the less refracted waves are those coming from the east The net longshore drift obtained when using the 2002 database is southwards, presenting slight inversions during the year. When using the predicted wave data for the studied period, the potential longshore drift is dominated by northward direction, in agreement with the observed inlet migration. The Itapocú river discharge does not present any relation with the observed inlet migration rates, although there seems to be a relation with the seasonal channel width variability. The surveyed morphological evolution is well related to the potential longshore drift, indicating that during the monitored period, the northwards inlet migration is being controlled by the wave generated longshore drift.

ASSUNTO(S)

inlet desembocadura morfologia refração de ondas e deriva litorânea morphology wave refraction and longshore drift

ACESSO AO ARTIGO

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