Evaluation of the coastal dynamics of the area of Baixio/Barra do Itariri, northern coast of the State of Bahia, using the Sistema de Modelagem Costeira (SMC-Brasil)

Abstract

The software Sistema de Modelagem Costeira (SMC-Brasil) performs various numerical models that allow for conducting short-, middle- and long-term analyses on beaches, thus contributing to coastal studies and management plans. The objective of the present study was to characterize wave and coastal current dynamics of the coastal area of the settlings of Baixio and Barra do Itariri, northern coast of the State of Bahia, producing wave propagation, sediment transport and flux, and inundation level. The wave statistical analysis for the study area, in terms of mean and extreme conditions, performed for intermediate waters, in Point 1 (Dow Point), indicated a predominance of waves from ESE and SE, with heights ranging between 1.61 and 3.25 m and periods, between 7.87 and 13.81 s. Shallow-water wave climate modelling was performed based on Point 1, analyzing others seven profiles along the coast. This analysis indicated a predominance of waves from SE, reaching approximately 1.4 m of height in the surf zone, and the occurrence of three rip currents. The calculation of mean annual longshore transport rates indicated the existence of a divergence zone in the direction of the net transport near Baixio and a northward increase in the percentage of incidence of waves from SE. The combination of storm events with positive meteorological tides, astronomical spring tides and extreme run-up values, can result in high-risk situations for ecosystems and properties, with great impacts on the studied coast, which currently presents high vulnerability to coastal erosion.