Analysis of sediment transport in the central region of Santos (SP, Brazil) through numerical modeling

Thiago Marques Coelho, Joseph Harari, Daniel Giancolli Ruffato

Department of Physical, Chemical and Geological Oceanography, Sao Paulo University, Sao Paulo, SP, Brazil. E-mail: thiagoceano@gmail.com

This study aimed to analyze the sediment transport in the central region of Baixada Santista (SP, Brazil) using the numerical model ROMS (Regional Ocean Modeling System) coupled to the numerical model SWAN (Simulating Waves Nearshore) in simulations representing the months of August 2009 and January 2010. The results suggested peaks in sediment transport, especially on the continental shelf and the Bay of Santos, during the passage of frontal systems, reaching values of 4,2 kg m⁻² s⁻¹ nearshore. The lowest rates of concentration of suspended sediment in the water column occurred during periods of neap tides, without the presence of strong winds and incidence of waves with high energy. In both simulated months, the bedload transport found in the coastal area was predominantly to the southwest, with the highest rates of transport observed in the month of August, with values of 1 x 10⁶ kg m⁻². The rate of sedimentation in the upper estuary has been on the order of 1 cm year⁻¹, in agreement with the data available in the literature. The numerical model represented the transport patterns of sediments found in the region in a satisfactory way.