Longshore sediment transport rate along Suarao and Cibratel beaches, Itanhaem, SP, Brazil

Longshore sediment transport rate is one of the most important features required for technical, economical and environmental feasibility assessment of Coastal Engineering projects. This study accomplished the longshore sediment transport rate calculation along Suarao and Cibratel beaches,located at the south Sao Paulo State littoral. The most accurate and reliable longshore sediment transport formulas available at the present time were used. Transport fates were obtained using wave data that was calculated considering shoaling and refraction of waves measured in a field survey in Una beach, 50 km far from Suarao and Cibratel beaches, in the period from 1982 to 1985. Besides the longshore sediment transport rate, this paper carried out the analysis of BOWD - Brazilian Oceanographic Wave Database - wave data of the period from 1956 to 1996 and identified the representative deepwater wave data for restricted area of the Sao Paulo south coast. Furthermore, a proposal of sedimentary balance for the study area was presented. It is concluded that the net longshore sediment transport in the Suarao and Cibratel beaches surf zone is southwestward and its calculated rate is between 350.000 and 550.000 m(3)/year. The representative wave data shows a large energetic and frequency dominance of the waves that come from the southeast sector. The BOWD wave data demonstrate a moderate potential for a preliminary evaluation of the wave climate of this area.