Fig. 25. Comparison of sediment-flux distribution measured at the downdrift traps, integrated over depth, and calculated values

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little is known within 1 cm of the bed, no estimate of

longshore flux at the plunging breaker line was

the near-bed sediment flux was made. Also, the sedi-

reproduced well. Sediment flux across the entire

ment flux was not calculated near the water surface.

mid-surf zone was significantly underpredicted for

Therefore, the integrated sediment flux did not include

the plunging case. The flux at the spilling breaker

the transport that occurred within 1 cm from the bed

line was overestimated. Reasons for this overestima-

and the upper 30%, or so, of the water depth.

tion are not clear. For the spilling-breaker case, sedi-

Overall, the cross-shore distribution of the calcu-

ment flux across most of the mid-surf zone was

lated longshore sediment flux compared reasonably

reproduced reasonably well, except close to the shore-

well with the measured flux at the downdrift traps

line, where an underprediction occurred. Because

(Fig. 25). These fluxes calculated from the product of

certain flux contributions near the bed and water

time-averaged current and concentration profiles are

Fig. 25. Comparison of sediment-flux distribution measured at the downdrift traps, integrated over depth, and calculated values.