panied by long-period wave motion as surf beat and edge waves, modifying the 

 transport regime that exists under purely regular waves. Other complicating 

 factors include the change in water level with the tide and the ambiguity in 

 specifying a representative grain size for the profile. 



222. The literature provides guidance on the problem of the difference 

 in transport under regular and irregular waves (see Kraus and Horikawa (1989) 

 for a more complete discussion). Hattori (1982) found better correlation 

 between the predicted cross -shore transport rate and the rate inferred from 

 his field measurements if mean wave height was used in the predictive expres- 

 sions instead of significant wave height. Mimura , Otsuka , and Watanabe (1987) 

 compared profile change and transport direction and rate produced in a small 

 wave tank in separate cases using regular and irregular waves. Among the many 

 interesting results, they found that the Sunamura and Horikawa (1975) (Table 

 3) criterion of erosion and accretion was successful (with modified value of 

 the empirical coefficient C) if mean wave height and period were used. 

 Profile change also proceeded at a slower rate for the irregular waves, 

 attributed to the presence of both "constructive" (accretionary) and "destruc- 

 tive" (erosional) wave components in the wave train. 



223. To examine the applicability of Equation 2 for expressing profile 

 type or erosion and accretion in the field, data sets published by Seymour 

 (1985) and Sunamura (1980) were used. Seymour (1985) provides plots of the 

 daily time history of contour movement between the berm and the approximately 

 1- to 2-m depth (relative to mean sea level) on three beaches- -Santa Barbara 

 and Scripps Beach, California, and Virginia Beach, Virginia- -together with 

 data on the significant wave height H^ and peak spectral wave period Tp at 

 a nominal depth of 10 m, tidal range, and median sand size at the respective 

 beaches. (It is noted that Figures 1 and 2 of Seymour (1985) should be 

 interchanged.) Sunamura (1980) provides wave and sediment data on major 

 erosion and accretion events in the literature and from his own field studies 

 for a total of 10 beaches located on various coasts around the world. 



224. The data of Seymour (1985) were censored to exclude days of minor 

 contour change as based on the rate of change of the deeper contours . Deeper 

 contours were used as the reference since the tidal range along the California 

 beaches (approximately 1.5-2 m) and Virginia Beach (approximately 0.5-1 m) 



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