response toward equilibrium. For larger wave heights, more wave energy is 

 dissipated along the beach profile; that is, the bar becomes larger and forms 

 farther offshore, causing more material to be moved before the equilibrium 

 shape is reached (lower a-values). Furthermore, greater wave energy is 

 required to move larger (heavier) sediment particles, implying more rapid 

 attainment of equilibrium (higher a-values) for larger grain-size beaches. 

 Depth-to-bar crest 



245. As a bar moved offshore, its height increased so that the depth to 

 the crest h^, was roughly constant during a run (except perhaps, at the very 

 first profile surveys) (cf. Birkemeier 1985a, Dette and Uliczka 1987). In 

 Figure 17(a and b) , the minimum depth on the bar, called the crest depth, is 

 plotted as a function of time for the CE and CRIEPI data. For some cases in 

 which a bar formed on an accretionary profile, the bar remained stationary, or 

 even moved slightly onshore, causing the crest depth to decrease. Also, if 

 two bars joined together, the crest depth changed abruptly since the inner bar 

 crest was located in more shallow water. 



246. A comparison between Cases 901 and 911 shows that even though the 

 equilibrium bar volume was almost the same (11.3 and 12.0 m'^/m, respectively). 

 Case 911 experienced a considerably larger fluctuation in depth at the bar 

 crest. Wave parameters and beach properties were identical for these two 

 cases, the only difference being a stepwise sinusoidal water level change 

 imposed in Case 911 to simulate a tide. Consequently, during cycles of 

 increased water level in Case 911, the depth at the bar crest increased and 

 the bar grew closer to the initial still-water (reference) level. During 

 cycles of lower water level, the depth at the crest decreased and a portion of 

 the bar eroded, causing the bar crest to move away from the initial location 

 of the still -water level. There was no significant time lag between water 

 level change and change in depth at the bar crest (see also Shepard 1950). 



247. The average depth at the bar crest was calculated for all profiles 

 comprising an individual case. This average was closely related to the 

 breaking wave height and showed little dependence on wave period and grain 

 size. If an inshore bar grew together with the main breakpoint bar, the most 

 seaward bar crest was used in determining the depth at the bar crest. The 



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