128. Wright et al . (1986) concluded from field measurements that bar- 

 trough morphology was favored by moderate breaker heights combined with small 

 tidal ranges. Short-period waves were the main cause of sediment suspension 

 in the surf zone, although long period waves were believed to be important in 

 the overall net drift pattern. 



129. Rushu and Liang (1986) proposed a criterion for distinguishing 

 between beach erosion and accretion involving a number of dimensionless 

 quantities. A new parameter consisting of the bottom friction coefficient, 

 critical velocity for incipient motion of the grains, and the fall speed of 

 the grains was introduced. 



130. Thomas and Baba (1986) studied berm development produced by 

 onshore migration of bars for a field beach at Valiathura, at the southwest 

 coast of India, and related the conditions for onshore movement to wave 

 steepness . 



131. Dette (1986), Uliczka and Dette (1987), and Dette and Uliczka 

 (1987a, b) investigated beach profile evolution generated in a large wave tank 

 under prototype -scale conditions. The tests were carried out with both 

 monochromatic and irregular waves for a dunelike foreshore with and without a 

 significant surf zone. For one case starting from a beach without "fore- 

 shore," monochromatic waves produced a bar, whereas irregular waves of 

 significant height and peak spectral period of the monochromatic waves did 

 not. The incident wave energy was different between the cases, however. 

 Sediment concentration and cross -shore velocity were measured through the 

 water column at selected points across the profile. 



132. Wright et al . (1987) investigated the influence of tidal varia- 

 tions and wave groupiness on profile configuration. Higher values of the wave 

 groupiness factor tended to correlate with beach states of more dissipative 

 character . 



133. Howd and Birkemeier (1987) presented 4 years of profile data 

 obtained at four different shore normal survey lines at Duck, North Carolina. 

 Corresponding wave and water level data were also published, making this data 

 set one of the most complete descriptions available of beach profile response 

 to wave action in the field. 



37 



