Longshore transport on the northeastern Brazilian coast and implications to the location of large scale accumulative and erosive zones: An overview

Using the average directions of the principal wavefronts that approach the northeastern Brazilian coast, which are coincident with the directions of the prevailing winds, a wave climate model was defined, for approximately 3000 km of coast by construction wave refraction diagrams. A resulting sediment transport model that was obtained by numerical modeling starting with refraction diagrams, taking into account the wave approach angles and their heights permitted the reproduction, on a regional scale, of the sediment dispersion pattern. Several drift cells were identified, the limits of which were based on alterations in the direction or intensity of potential net longshore drift. Although also dependent on other factors such as the supply of fluvial sediments to the coastal zone and to wind activity, the coastal sections that present progradation, erosion or non-deposition, can be reasonably explained, in a first order approximation, by these variations. As a generalization, geomorphic drift indicator match patterns of regional scale sediment dispersal.