Coastal Dunes along Rio de Janeiro Coast: Evolution and Management

Coastal dunes occur in restrict areas along Rio de Janeiro Coast. These environments have been subjected to a wide variety of investigations over the time, using different approaches and issues. In this research we mapped three sites of transgressive coastal dunes, identified along Rio de Janeiro state, including morphodynamics aspects, occupation and implications for the coastal management. Different types of foredunes were identified along the Paraiba do Sul delta. The main mechanism for dune development is associated with erosional and depositional phases of coastline, participating the sedimentary budget between beaches, shoreface and fluvial inputs that promotes formation of two types of foredunes. The transgressive evolution of foredunes southward to Paraiba do Sul river mouth promoting severe erosion along Atafona beach that affects buildings and the urban structure. Other area is located between Cabo Frio and Cabo Búzios, where the coastal plain is characterized by a complex of foredunes, barchans and parabolic dunes. The dynamics of this complex system is govern by northeast trade winds. The main coastal problem identified in Cabo Frio region is associated to planning new resorts and urban structure above the dunes. We concluded that the occupation of these areas with no criteria of coastal management and respect for Brazilian laws promotes critic conflicts.