The Sandy Beaches of the States of Sergipe-Alagoas

The beaches of Sergipe and Alagoas illustrate the role of geological inheritance and the effect of sediment grain size in controlling beach morphodynamics. Overall, under the same wave energy levels, beaches located on prograding sections of the coast have finer sediments and are dissipative, whereas on coastal sections starved of sediments the sand is coarser and the beaches are more reflective. This results from the fact that distant sourced sands, typical of large rivers, such as the Sao Francisco, are typically fine. These sands are transported southwards feeding the Sergipe shoreline, where dissipative beaches dominate.