will be necessary to consider the wave setup caused by these breaking 

 waves. 



In studies of coastal flooding by hurricanes, the engineer could 

 choose to include the effects of wave setup in the water level estimate. 

 This report could be used to compute that setup for both cases (Fig. 1) 

 where runup values are not desired. 



Additional methods for estimating wave setup are given in James (1974) 

 and Goda (1975) . Application of these methods is not discussed in this 

 report. 



II. EQUATIONS 



All equations in this memorandum have been previously presented in 

 the SPM. Equation 3-48 of the SPM shows that the net wave setup on a 

 shoreline is the algebraic sum of the wave setup and wave setdown, or 



Sy = AS + s^, , CD 



where Sy is the net setup, AS is the wave setup, and S^, is the 

 wave setdown; S^ is defined as a negative value. 



Equation 3-46 of the SPM defines the setdown, Sj,, as 



gV2 (H>)2 T 



S& -— > (2) 



6477 d^ 3/2 



where 



g = gravitational acceleration, 



H^ = equivalent unrefracted deepwater wave height, 



T = wave period, 



d^j = depth of water at breaking wave. 



Note that H^ = H^K^, and where K^ = 1, H^ = H^. 



Equations 2-91, 2-92, and 2-93 of the SPM define d, in terms of the 

 breaker height, H^^, period, T, and beach slope, m. 





a 



2 



(3) 



10 



