beach profile response as compared to a simulation with no smoothing. A more 

 thorough discussion of values of the transport rate coefficient is given in 

 Part Vll describing application of the numerical model. 



368. It was not possible to relate the transport rate coefficient to 

 wave or beach properties. In a numerical model the transport rate coefficient 

 functions largely as a calibration parameter to give the proper time scale of 

 profile change. 



369. In the regression analysis between transport rate and energy 

 dissipation per unit volume, other beach and wave parameters were added to 

 quantify their influence. For the cases where the local beach slope showed 

 some influence on the transport rate, the coefficient in the regression 

 equation was typically small, on the order of 0.0006 mVsec. The equilibrium 

 energy dissipation was determined from the constant term in the regression 

 equation and varied considerably between the runs evaluated, although the 

 grain size was the same for the studied cases. This variation was probably 

 due to the scatter in the data relating transport rate to energy dissipation, 

 making the least-squares estimate of the constant in the regression equation 

 less reliable. However, two of the cases resulted in equilibrium energy 

 dissipations that were somewhat smaller than the values given by Moore (1982), 

 who used natural beach profiles to determine this parameter (108 and 134 

 Nm/(m^sec) from the present data compared to Moore's value of 170 Nm/m^sec) . 



370. The purpose of the previous analysis was to emphasize the close 

 relationship between wave energy dissipation per unit volume and magnitude of 

 the transport rate in zones of broken waves. Although the number of satis- 

 factory cases for obtaining quantitative information about wave height and 

 associated sand transport rate distribution was small, the relationship 

 between the two quantities was clearly evident. All of the studied cases 

 encompassed beach profiles which experienced erosion of the foreshore and bar 

 formation in the vicinity of the break point. It is expected that profiles 

 with accretion on the foreshore will also exhibit transport rates that are 

 related to the energy dissipation per unit volume, although it was not 

 possible to directly confirm this assumption by means of the present data. 



151 



