x = o 



Figure 21. Slope and shelf. 



The solution of equation (177) is plotted in Figure 22. As shown in the 

 figure, the reflection coefficient approaches zero as the slope length 

 I approaches the length of the incident wave L 1 . 



0.8 r 



-27T//L, 



0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 

 I 

 L. 

 Figure 22. Reflection coefficients (from Kajiura, 1963). 



************** EXAMPLE PROBLEM 6************** 



GIVEN: An incident wave which is 0.6 meter (1.97 feet) high and has a 

 period of 20 minutes, approaches the coastline through water 2,500 

 meters deep and passes onto a shelf where the water depth is 100 meters 

 at a zero angle of incidence (6} = 0) . The effective length of the 

 slope between the two water depths is £ = 24,000 meters (14.9 miles). 

 It is assumed that the slope is defined by equation (175) and that 

 energy is conserved; i.e., the total of the reflected and transmitted 

 wave energy equals the incident wave energy. 



77 



