DOI: 10.5281/zenodo.5061107
title: Data related to "Near-bed sediment transport under bichromatic, erosive wave groups in large-scale experiments"

description: Abstract: This paper presents novel insights into hydrodynamics and sediment fluxes in large-scale laboratory experiments with bi-chromatic wave groups. An Acoustic Concentration and Velocity Profiler provided detailed information of velocity and sand concentration near the bed including suspended sediment and sheet flow transport. The morphological evolution was characterized by offshore migration of the outer breaker bar. Decomposition of the total net transport revealed a balance of onshore-directed, short wave-related and offshore-directed, current-related net transport. The short wave-related transport mainly occurred as bedload over small vertical extents. It was linked to characteristic intrawave sheet flow layer expansions during short wave crests. The current-related transport featured lower maximum flux magnitudes but occurred over larger vertical extents. As a result, it was larger than the short wave-related transport in all but one cross-shore position, driving the bar's offshore migration. Net flux magnitudes of the infragravity component were comparatively low but played an important role for total net transport in certain cross-shore positions. Net infragravity flux profiles sometimes featured opposing directions over the vertical and the fluxes were linked to a standing long wave pattern and phase lag effects of sediment suspension linked to the wave groups. About the data: The data on beach profile (from mechanical profiler), velocity (from ACVP and ADV), sand concentration (from ACVP and OBS) and water surface elevation (from RWG, AWG and PT) measurements is given in .mat (MATLAB) files. The folder “profiles” contains the measurements from the mechanical profiler before and after each test. To save time, only the morphologically active section of the profiles was measured. Additionally, the folder contains the initial profiles at the start of a sequence (after application of the benchmark waves). Here the full profile was measured. The structure “MobFrame” contains the absolute cross-shore position of the mobile frame (from which detailed measurements were taken) in the considered tests. The folder “ACVP” contains structures with ensemble-averaged velocity and concentration measurements in vertical reference to the undisturbed bed level or a few bins below it (zeta-coordinate system) sampled at 50.5051Hz. For better interpretation of the measurements, it also features the ensemble-averaged intrawave instantaneous erosion depth (bed elevation) and the upper limit of the sheet flow layer. The folder “ADV” contains structures with the ensemble-averaged ADV data of each test sampled at 100Hz. Apart from the velocity components of each ADV it contains the vertical elevation of each ADV with respect to the ACVP transceiver. The ADV measurements were not subject to the same vertical referencing procedure that was described in the paper for the near-bed ACVP measurements and a more or less constant distance to the bed was assumed. The folder “OBS” contains structures with the ensemble-averaged OBS data of each test sampled at 40Hz. Apart from the concentration measurements in each OBS bin it contains the vertical elevation of the bin with respect to the changing bed (as described in the data treatment section of the paper). The folder “ETA” contains structures with the ensemble-averaged water surface elevation measurements in many different absolute cross-shore locations in the flume sampled at 40Hz.