Relative Wave Height (H/H tp ) 

















a 



Wave 



Crests 









































b 



1,0 - 



"7 



0.8 _ 



0.6 _ 







__c__ 



b 







i 



i 



0.0 



— 0.5 



— 1.0 



0.4 - 

 0.2 - 

 00 





a ... 



c 



i 



*u- 



i 



100 200 300 400 500 



Distance Alongshore (m) 



Fig. 3. Distribution of relative breaking wave height, H/H tp 



For K T = 0.5, the relative wave height in the shadow region is 0.5. Since 

 the wave height in the shadow region is now greater as compared to the case of 

 no transmission, wave diffraction in the illuminated region must weaken. As 

 shown by curve a , the wave height to the right of the structure is half-way 

 between the curve for pure diffraction and the curve depicting no diffraction 

 (H/H t = 1.0). Since diffraction acts to transfer energy from areas of higher 

 waves to lower waves, waves transmitted through the breakwater will not 

 diffract into the illuminated region, and the transmitted wave height b 

 drops sharply from 0.5 to zero. The alongshore distribution of the combined 

 wave height C meets line a in the illuminated region, half-way between 

 the diffraction curve and the curve H/H tp = 1.0. 



For Kj. = 1.0, waves incident to the breakwater pass undiminished. Dif- 

 fraction does not occur, and wave heights in the shadow and illuminated 

 regions are equal. The relative wave height on either side of the separation 



46 



