700 



Shoreline position (ft) 



Verification 



K1 - 0.52 -- K2 - 0.22 D50 - 0.2 



L '/ZZ. VZZZZZZZZ] 



200 400 600 800 1000 



Distance alongshore (ft) 







1200 



Figure 44. Model sensitivity to changes in Kl , K2 , and D50 



Wave transmission and offshore waves 



403. Figure 45 illustrates model sensitivity to changes in the trans- 

 mission of the breakwaters and to the offshore wave height and direction. The 

 solid line represents a case where all three transmission coefficients were 

 decreased by 0.2 resulting in K T of 0.3, 0.02, and 0.1 as compared with the 

 original values of 0.5, 0.22, and 0.3, respectively, from the west to east 

 breakwater. The breakwaters were constructed at the same time and have the 

 same cross sections. Therefore, the transmission coefficients should be 

 equal. Simulations with a single value of K T close to the average of those 

 above also gave good results, but the calculated beach planform could be made 

 to closely reproduce the measured planform by using unequal values. From the 

 pragmatic perspective of obtaining the best calibration, differences in K T 

 values over the determined range were considered acceptable. 



404. With the exception of the western part of the beach, smaller 

 transmission coefficients result in larger salients without a corresponding 



171 



