Variations of the shoreline on Santos and São Vicente bays

Abstract

The region of Santos and São Vicente, central seacoast of São Paulo State, in Brazil, is a really important touristic and economic region (i.e., the port of Santos is the largest one of the country). The work aims to study the variations along the shoreline of the beaches of this area. Many changes were made on the beach region, mainly to implement a better urban infrastructure and this caused a large variation in some parts of the shoreline. The comparison of air photographs from different dates clearly pointed that these changes were especially noticed nearby Urubuqueçaba Island and the Outfall of Santos, where the sediment retention presents a reflection in the erosion which occurred in other parts along Santos beach. The artificial closing of the access between São Vicente Island and Porchat Island in São Vicente caused a deficit of sediments all over the beaches on São Vicente Bay. The erosive process caused by this action required some restraint work which worsens the coastal erosion issue. Most of the erosion and/or enlargement processes on these beaches are mainly caused by human intervention, and this makes it difficult to distinguish the influence caused by natural causes such as the increasing of the intensity of frontal systems and the sea level changing.