7 b = 0.72 + 5.6m (18) 



Equation 18 described the experimental data well for slopes 1/20 and milder. 



30. Goda (1970) developed curves from existing laboratory data for 

 beach slopes ranging from 1/10 to 1/50. Goda noted that bottom slope affects 

 not only breaker height, but also breaker depth. 



31. Weggel (1972) developed a relationship for ft), based on the form 

 of Munk's (1949) relationship for fy, as 



F(m) 





+ G(m) (19) 



Weggel determined the functions F(m) and G(m) empirically from the Iversen 

 (1952) data, where 



F(m) = D x [l + m - G(m)] (20) 



G(m) = [D^l + m) - D 2 (1.715 - 0. 185<T 28m ) ] (21) 



and 



D x = (0.01 + 0.5m) 1 / 3 (22) 



D 2 = (0.01 - 0.01e- 28m ) 1/3 (23) 



where D x and D 2 are empirical functions for breaker height (Weggel 1972) . 

 Weggel commented that use of Equation 19 became questionable for m > 1/10 

 and H /L > 0.06 . 



32. Weggel (1972) also developed an equation for the breaker depth 

 index from previous laboratory data (Iversen 1952, Reid and Bretschneider 

 1953, Galvin 1969, Weggel and Maxwell 1970, and Jen and Lin 1971) collected 

 on slopes of 1/5, 1/10, 1/15, 1/20, and 1/50. The resulting relationship is 

 expressed as 



H b 

 7b = b(m) - a(m) — (24) 



L„ 



22 



