Sediment transport partitioning in the swash zone of a large - scale laboratory beach

Swash zone sheet flow and suspended sediment transport rates are estimated on a 14 coarse sand beach constructed in a large-scale laboratory wave flume. Three test cases under 15 monochromatic waves with wave heights of 0.74 m and wave periods of 8 and 12.2 s were 16 analyzed. Sediment flux in the sheet flow layer exceeds several hundred kg m s during both 17 uprush and backwash. Suspended sediment flux is large during uprush and can exceed 200 kg m 18 2 s. Instantaneous sediment flux magnitudes in the sheet layer are nearly always larger than 19 those for suspended sediment flux. However, sediment transport rates, those integrated over 20 depth, indicate that suspended load transport is dominant during uprush for all cases and during 21 the early stages of backwash except in the case for the 12.2 s wave case when the foreshore was 22 steeper. Results could not be obtained for an entire swash event and were particularly truncated 23 during backwash when water depths fell below the elevation of the lowest current meter. 24