Titre/Title : Sheet flow in the swash and surf zones
Contact : Julien Chauchat (équipe MEIGE)
Résumé/Abstract : The swash and surf zones are highly dynamic regions of the nearshore that undergo constant morphological change. Obvious changes are manifested through beach erosion/accretion processes, beach face steepening/flattening and surf zone sand bar migration. This morphologic variability arises from spatial gradients in sediment transport driven by waves and currents. The sediment transport itself is generally subdivided into 2 components: suspended load and bed load. There is another type of sediment transport, sheet flow, that may be categorized as a special type of bed load transport. Sheet flow occurs in the direct vicinity of the bed, is driven by large shear stress and has been described as a “carpet” of sand in motion. Our research group has developed a unique sensor to profile the sheet flow sediment concentration in different nearshore environments. The presentation will describe this novel sensor and include results from recent large-scale laboratory and field data collected in the swash and surf zones.