to predict the development of main morphologic features of the beach profile. 

 Available equilibrium distributions of the net transport rate could be 

 classified almost exclusively into three main types, two types of which corre- 

 spond to either onshore or offshore transport along the profile. Transport 

 distributions with one onshore and one offshore peak were not common and 

 occurred mainly for cases which fell close to a derived line delineating bar 

 profiles and berm profiles. As a result, the assumption of a unidirectional 

 transport rate along the profile should give a reasonable first approximation 

 in most cases for describing the overall profile response to incident short- 

 period waves. 



375. Division of the profile into four zones with different transport 

 properties, based in part on general observations of nearshore wave dynamics, 

 proved to be a fruitful approach both from the conceptual and predictive 

 points of view. The net transport rate in zones of broken waves, where the 

 most active transport is expected to occur, showed good correlation with the 

 wave energy dissipation per unit water volume. The net transport rate in the 

 prebreaking zone decayed exponentially with distance offshore. On the 

 foreshore, the net transport rate showed an approximately linear behavior 

 decreasing in the shoreward direction from the end of the surf zone. More 

 data on the transport rate in the foreshore are needed to better understand 

 physical processes there. 



376. Quantitative information on the net cross-shore transport rate is 

 difficult to obtain in the field due to the limited resolution in time and 

 space of profile surveys, number of instruments that can be deployed, contami- 

 nating effects of longshore sand transport, and changing wave conditions. In 

 this respect, data from large wave tanks provided valuable insight into the 

 behavior of the net cross -shore transport rate and enhanced the possibility of 

 modeling beach profile change. Although monochromatic waves were used in the 

 large wave tank experiments, it is expected that the main features of the 

 transport rate are representative of processes associated with random waves in 

 the field. This hypothesis is tested in Part VII where model predictions are 

 compared with field observations. 



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