Appendix. Resulting spectra at gradually decreasing depths for a given case 

 are shown in Figure 1. This analysis provides the wave height prediction 

 curves shown in Figure 2. These curves provide the nearshore significant wave 

 height, Hg, at a given water depth which is related to the total energy, Ej, 

 in the nearshore wave spectrum by 



Hg = 4v^ 



given the fetch length, the overwater windspeed, and the deepwater wave height. 

 Note that in Figure 1 there is a slight shift in the wave period toward lower 

 frequencies as the spectrum moves into shallow water. Later work will attempt 

 to quantify this shift and incorporate bottom friction effects. 



III. USE OF CURVES 



There are certain restraints on the use of the curves which are as follows: 



(1) Curves are designed to be used for fetch-limited, wind-generated 

 waves in deep water over short fetches, i.e., up to 62 miles (100 kilo- 

 meters) . 



(2) This analysis includes only the wave steepness criterion and 

 shoaling. It does not reflect other energy losses such as refraction, 

 friction, or percolation (parallel bottom contours are assumed) . 



(3) The fetch length, F, is strictly the straight-line fetch 

 unless the water body is irregularly shaped where the fetch would be 

 based on an average over a 24° quadrant. 



E(tl -s) 





U:49.2 fl/$|i5ni/s) 





^ F:65, 600 II (20,000m) 

 / \ Curve 1 





/ \ Oeepwoler 





1 Y JONSWAP 





1 1 Spectrum 





/ \ \ d=l3l.2 ll(40m) 





//,\ Vv \ y'''^^^ lldOm) 





/r \ \ ^^<^ d=l9.7 ri(6m) 



1 



/ ^\5\V\ d=l3.lll(4m) 



0.2 0.3 



Frequency 



0.4 



Figure 1. Transformation of JONSWAP spectrum in shallow water. 



