c . Evaluation of Parameters of Interest. To evaluate the nearshore param- 

 eters, use the figure in Appendix B having the offshore slope, m, and offshore 

 wave steepness (Ho/L ) closest to the values of interest. Enter the value of 

 d/HJ, on the ordinate of the graph, and select the curve of the parameter of 

 interest. Five dimensionless parameters are presented: 



Curve 



Description 



1 



V H i 



2 



^rms/^o 



3 



H/H^ 



4 



H s /H-, 



5 



Hi /% 



Use the abscissa on the right for curve 1 (setup) and the left abscissa for 

 curves 2 to 5. Setup has an enlarged scale because it is small compared to 

 wave height. 



4. Example Problems to Determine Nearshore Conditions (Neglecting Refraction) , 



************** EXAMPLE PROBLEM i**************** 



GIVEN : The offshore slope is 1/100, tLj, = 3.0 meters, and T s = 14 seconds. 



FIND: The rms , mean, significant, and maximum wave heights and mean water 

 level at a Stillwater depth of 6.0 meters. 



SOLUTION: The refracted wave steepness from equation (6) is 



H 



o 3.0 



L (156(14) 2 ) 



0.01 



and the depth to deepwater wave height ratio is 



d_ 6.00 



From Figure B-4 in Appendix B, 



2 

 Hi 3.00 







Ratio 





Value 



Curve 



Variable 



value 

 -0.02 





Cm) 



1 



s w 



= -0.06 



2 



Hprns/H^ 



0.87 



"rms = 2.6 



3 



H/H^ 



0.81 



H 



= 2.4 



4 



H s /H' 



1.23 



H s 



= 3.7 



5 



Hi nv 



1.57 



H i 



= 4.7 



Mean water level = d + Sy = 6.00 - 0.06 = 5.94 meters. 



16 



