JUL -SEP 80 

 JUL -SEP 81 



1.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 11. 0- 12.0- 14.0- 17.0- 

 2.9 3.9 4.9 5.9 B.9 7.9 8.9 9.9 10.9 11.9 13.9 16.9 LONGER 

 PERIOD, SEC 



Figure 20. 1981 and 1980 sununer wave period 

 distributions for gage 625 



Wave direction 



77. For many engineering applications, such as sediment transport 

 computations, an understanding of the directional characteristics of a wave 

 field is as important as measurement of the wave energy. Visually observed 

 angles of the primary wave train (i.e., the wave train having the largest 

 heights) can provide qualitative climatological information useful in identi- 

 fying seasonal trends in wave direction. Wave roses generated for 1981 were 

 based on visual measurements of the direction from which the primary wave 

 train approached relative to true north; these measurements were made daily 

 (near 0700 EST) at the seaward end of the FRF pier. Wave height was 

 determined from the pier-end Baylor gage (625) at a corresponding time. The 

 angles shown here are figured relative to true north, and the pier axis (con- 

 sidered perpendicular to the beach at the FRF) is oriented 69°58' east of 

 true north; consequently, wave angles greater than approximately 70 deg imply 

 the waves were coming from the south side of the pier. 



78. During 1981, 46 percent of waves approached from north of the pier, 

 and 51 percent from south; 3 percent were shore normal (see Figure 21). 



46 



