where 0^0 is the value of 0^ when 5^= 0. It is noted that Equations 6. 1,6.3, and 6.6 

 underpredict variability of erosion somewhat, but more data are required to better 

 quantify these relations. Equations 5.10 and 6.1 through 6.6 define the damage profile 

 shape and alongshore variability as a function of mean damage without regard to wave 

 conditions. 



The temporal variation of mean damage is given by Equations 6. 15 and 6. 16 



5(0 = 5(r„) + 0.025(N;5 7-„°"(/0-25 - rf ^) for t^<t<t„^^ 



S{t) = 5(r„) + 0.022(A^„„)-^(7;)-o-25(rO-25 - ?»■") for t^<t<t„^, 



for time domain and frequency domain wave statistics, respectively. These formulas 

 can be used for predicting mean damage S, where the wave height and period vary in 

 steps. The formulas fit the data well for Series A', B\ and C, with systematic variations 

 of water depth and wave height. The equations are shown to fit the trends of damage 

 progression well for Series D', E', F', and G', where the peak wave period and stone 

 gradation were varied. Damage initiation, where only 1 or 2 stones moved, was 

 consistently underpredicted by more than a standard deviation for Series D' through G'. 

 This appears to be due to the variability in damage initiation. It is shown that the 

 prediction is significantly improved if the damage progression is begun immediately 

 after the initial profile adjustment or 1000 waves. The initial profile adjustment may 

 need to be accounted for in test series with relatively small cumulative damage. Also, 



150 



