where K^ q-, is the decay factor defined for f^ = 0.01 and K^ is the 



decay factor defined for the actual bottom friction with water depth, d, 



initial wave height, H-, windspeed, U, and segment length. Ax, re- 

 maining the same. 



For wave growth, a segment with bottom friction ff > 0.01 would 

 require a longer segment length for waves to grow to a given height than 

 the length that would be required where f f = 0.01. Therefore, the seg- 

 ment with greater bottom friction is equivalent to a shorter segment with 

 ff = 0.01. As an approximation, the shorter adjusted segment length, F^, 

 is defined as 



F^ = a Ax , (11) 



where Ax is the actual segment length (see Fig. 13) . 



For wave decay, a fetch segment with bottom friction f f > 0.01 

 would require a shorter length for waves to decay to a given height than 

 would be required where f f = 0.01. Therefore, the segment with higher 

 bottom friction is equivalent to a longer segment with f f = 0.01 (see 

 Fig. 14) . The longer adjusted segment length, F^, in this case is 

 defined as 



F„ = a„ Ax , (12) 



where 



ar> = — = " — . (loj 



" (1 - Ky-.oi) 



IV. WAVE GROWTH IN SHAMOW WATER 



From Figure 1 or equation (3), for any given water depth, windspeed, 

 and fetch length, a maximum significant wave height, Ugrn, which would 

 be generated can be defined. If the initial wave height, H^, at the 

 seaward or beginning edge of the fetch segment is less than Hgrn' ^^ ^^ 

 assumed that the wave will grow to a higher height as discussed previously. 



To determine the wave growth, it is necessary to first determine an 

 equivalent fetch length, Fg, for the initial wave. This is obtained 

 directly from Figures 1 to 12 losing the given windspeed and water depth. 

 Secondly, the adjusted fetch, F^, is determined lising equations (10) 

 and (11) and Figure 16. The total fetch is then given as 



F = Fg + F^ • C14) 



30 



