FLUXOS GRAVITACIONAIS DE SEDIMENTOS SUSTENTADOS POR ONDAS: SUA IMPORTÂNCIA COMO AGENTES NO TRANSPORTE SEDIMENTAR COSTEIRO

Código

PAP017

Autores

Eduardo Puhl, Julia Pelegrini

Tema

PROCESSOS HIDROSSEDIMENTOLÓGICOS E MORFOLÓGICOS: FLUVIAIS, LACUSTRES E COSTEIROS

Resumo

The coastal zone is subject by several sources and sinks of sediment which are influenced by differentfactors: waves, current,tides, wind, etc.Understanding the effect of these elements into the coastal zone isessential tocoastal management.Density currents can be supported by the actionof waves and currentsin order to transport sediment away from the coast;these flows were observed in field campaignsand are called Wave-Supported Sediment Gravity Flows. They start actingafterhigh energy storms which suspend the sedimentclose to the shore, after this a density current is formed taking out sediment from the coast. The lack of sediment at the coast can lead to several problems: shoreline recession, loss of natural habitats, increasingthe frequency of coastal flooding, etc.In this work physical modeling is used to investigate the ignition and development of these currents.The experimentused a small wavechannel 0.98 m long equipped witha manual wave generator.Different waves were formed according to thefrequency and amplitude of the oscillation of the wave generator. At the other end of the channel anartificial beach was built using granulated Melamine. At the end is observedthat the generation of the flow is helped byhigh frequency waves, high slopes at the shore and by varying wave energy gradually along the experiment.Besides improving the knowledge of the dynamics of the sediment at the coast,these results can help numerical models at validation and calibration steps.