calculated from surveys taken before and after the measurement of the wave 

 height distribution was used. No significant correlation was found that was 

 consistent for all cases between any other parameter studied and the transport 

 rate. For some cases, there was a positive correlation between transport rate 

 and beach slope. 



364. A linear regression equation relating the transport rate to energy 

 dissipation per unit volume and local beach slope was least-squares fitted to 

 the data. The regression relationship explained about 50-70 percent of the 

 total variation in the data for the different cases studied, in which local 

 beach slope accounted at most for 10 percent of the total variation. 



365. Kriebel and Dean (1985a) assumed that the cross -shore sand trans- 

 port rate was proportional to the excess energy dissipation per unit volume 

 over a certain equilibrium value of energy dissipation, which was defined by 

 the amount of energy dissipation per unit volume a beach with a specific grain 

 size could withstand (cf. Part VI). From the regression analysis between wave 

 energy dissipation per unit volume and transport rate, it was possible to 

 obtain an estimate of the transport rate coefficient corresponding to the 

 proportionality constant used by Kriebel and Dean (1985a). 



366. For the four cases intensively studied, the average value of the 

 transport rate coefficient was determined from regression analysis to be 

 1.1 10'^ ni^/N, which is approximately half the value originally obtained by 

 Moore (1982). Moore developed a numerical model of beach profile change using 

 a transport equation for the cross -shore sand movement in which the transport 

 rate was proportional to wave energy dissipation per unit volume. He arrived 

 at a transport coefficient of 2.2 10'^ m*/N by calibration using profile 

 change measured in one CE case and field measurements from Santa Barbara, 

 California. 



367. Two major causes are believed responsible for the difference in 

 values obtained. First, Moore (1982) inferred the transport coefficient by 

 comparison of simulated profile change and measurement, not directly between 

 wave energy dissipation per unit volume and measured transport rate as done 

 here. Second, considerable smoothing of the calculated transport rate was 

 used in Moore's model. By smoothing the energy dissipation along the profile, 

 a larger value of the transport rate coefficient is needed to achieve the same 



150 



