São Francisco River mouth: Bedforms characterization associated to flow conditions

The São Francisco River is located in the northeast portion of Brazil. It is an important river from economic and social viewpoint. This river has been cited, in the literature, as the classical example of wave-dominated delta, however, changes in water discharge due to the construction of seven dams affected significantly river hydrodynamics and sediment transport ca pacity resulting in a severe coastline retreat. The purpose of this study is the classification and understanding of the subaqueous bedforms behavior using hydrodynamic and sedimentological data. The sonographic data was acquired with an Edgetech Side Scan Sonar model 272-TD, the hydrodynamic data were acquired using an RDI Acoustic Doppler Current Profiler (ADCP) Rio Grande, and the sediment samples were collected using a Van-Veen grab sampler. The data showed that the river bottom is very uniform in sediments types but has a great var iety of bedforms according to size and type, furthermore it changed according to wa ter flow conditions.