The wave data have been evaluated and analyzed for the smooth 

 bottom conditions, and partly completed for the rough bottom and the 

 case with "vegetation" . 



The data indicate that Sverdrup-Munk-Bretschneider curves may be 

 used to predict the wave heights for relatively deep water. As is to 

 be expected in shallow water, however, the wave heights are considerably 

 lower than predicted by the curves, depending upon the depth of the 

 water. The experimental results indicate that the depth starts to 

 affect the wave heights at approximately d/H < 5. Here d is the 

 actual depth at the location of wave measurements and H the deep-water 

 wave height as predicted by the use of above named curves for the given 

 fetch and wind velocity. 



The wave period in the generating area is also affected by the 

 depth of water resulting in shorter wave periods than predicted by 

 Sverdrup-Munk curves. The experimental results indicate that the 

 depth starts to affect the wave period at approximately d/l o < 0.2. 

 Here d is again the actual depth of the location of wave measurements 

 and L the deep-water wave length as computed by the formula L r 5.12 T , 

 where T is the wave period for deep water and could be predicted by 

 the curves. 



Further it was found that the maximum wave height for a group of 

 100 waves is 1.3U times that of significant wave height H1/3 for the 

 same group. This is exactly the same value that was found for the 

 Lake Okeechobee wave data and is lower than found for deep water in 

 oceans (approximately 1.60) . 



The relationship between the mean and significant wave heights 

 was found to be H me an ■ 0.68H]/3, which is somewhat higher than the value 

 of 0.60 for Lake Okeechobee waves. 



III. S cripps Institution of Oceanography, Contract No. DA-l+9-055-eng-3, 

 Quarterly Progress Report No. 20, April to June 19Sh 



Frequency-distribution curves have been computed for the maximum 

 onshore and offshore components of orbital velocity, and for the heights 

 and periods of the waves generating them. 



Periodic measurements of sand-level changes with reference rods 

 have now extended over a period of 15 months at three of the stations. 

 The maximum changes during this period were 0.12, 0.15, and 0.06 foot 

 in areas where the water depth is approximately 30, 52, and 70 feet 

 respectively. 



During the past three months the valley heads leading into Scripps 

 Canyon have continued to shoal with a fill amounting to a maximum of 

 k feet bringing these valleys back close to the highest points on record. 

 However, there was some localized deepening in Sumner Valley which 

 amounted to hz feet. This deepening did not persist in the adjacent 

 lines but the record seems to leave little doubt of its having occurred. 



16 



