206. Iwagaki and Noda (1963) used a combination of two nondimensional 

 parameters, Hg/Lg , and the ratio between deepwater wave height and median 

 grain diameter, H^/D , to predict erosion and accretion (bar/berm formation). 

 Nayak (1970) approached the problem in a fashion similar to that of Iwagaki 

 and Noda (1963) but included the specific gravity in the denominator of 



Ho/D . 



207. Dean (1973) developed a popular heuristic model of sand transport 

 in which most of the cross -shore transport in the surf zone is assumed to 

 occur as suspended load, by which the sediment fall speed emerges as a 

 significant parameter. The bar/berm predictive criterion developed by Dean 

 (1973) is expressed in terms of Hq/L^ and ww/gT , in which g is the 

 acceleration due to gravity. Dean (1973) also introduced the dimensionless 

 fall speed parameter H/wT in a conceptual model of suspended sediment 

 movement and developed it as an indicator of cross-shore transport direction. 

 Gourlay (1968), Nayak (1970), and Kohler and Galvin (1973) also used the fall 

 speed parameter as a descriptor of beach profile processes, based mainly on 

 dimensional considerations. 



208. Sunamura and Horikawa (1975) and Sunamura (1980) used three 

 parameters in their criterion to predict erosion and accretion, H^/Lq , 



D/Lq , and beach slope, tan/3 . Different values of the empirical coefficient 

 in the equation delineating erosion and accretion (bar/berm profiles) were 

 obtained for laboratory and field conditions, and it is of interest that the 

 same functional form of the equation proved valid for both situations. 



209. Hattori and Kawamata (1981) developed a criterion for onshore and 

 offshore sand transport based on parameters essentially identical to those 

 used by Dean (1973), except that the initial beach profile slope was combined 

 with the wave steepness parameter. 



210. In a milestone experiment using the first LWT in the world, 

 Saville (1957) recognized that the deepwater wave steepness criterion of 0.025 

 was not accurate for distinguishing bar and berm profiles as produced by large 

 waves in the field. For his LWT experiments, which used regular waves, bar 

 profiles occurred at much smaller values of wave steepness (as small as 0.0028 

 in the CE experiments), whereas corresponding cases scaled down to 1:10 ex- 

 perienced marked berm buildup. 



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