gT2 



= 0.003830 



— = 1.31 



H^ = 23.27 feet 



At this point, the problem can be completed by either an algebraic 

 solution of equations (7) and (8) or by using Figure 3 with 



then 



% = 



23.27 



feet 





0. 



005019 



and m = 



0. 



05 



' 



5^ = 



0. 



111 





Sy = 2.6 feet 



Therefore, the new water level at the beach will be +2.6 feet MLW, 

 which will result in a depth of 3.6 feet at the toe of the beach 

 slope. The computation of the maximum runup height on the beach 

 would involve the determination of the maximum breaking wave and 

 runup for a range of wave periods. The highest runup elevation 

 computed would be used for design purposes. 



************** EXAMPLE PROBLEM 7*************^ 



GIVEN : A mathematical model simulation indicates that a particular 

 section of coastline will experience a storm surge of +15 feet for 

 a particular hurricane. The backshore area is protected by a contin- 

 uous line of sand dunes whose lowest elevation is at about +20 feet. 

 An estimate of the deepwater significant wave height and period yields 

 H^ = 30 feet and Tg = 12 seconds. The beach slope is a constant 

 m = 0.05. 



