Wave period T p is defined as the period associated with the maximum 

 energy band in the spectrum, which is computed using a 3-point running 

 average band on the spectrum. The peak period is reported as the reciprocal 

 of the center frequency (i.e., T = 1 /frequency) of the spectral band with the 

 highest energy. A detailed description of the analysis techniques is presented 

 in Andrews (1987). 2 



Results 



The wave conditions for the year are shown in Figure 9. For all four 

 gauges, the distributions of wave height for the current year and all years 

 combined are presented in Figures 10 and 11, respectively. Distributions of 

 wave period are presented in Figure 12. 



Multiple-year comparisons of data for Gauge 1 1 1 actually incorporate data 

 for 1985 and 1986 from Gauge 640 (a discontinued Waverider buoy previous- 

 ly located at the approximate depth and distance offshore of Gauge 111) and 

 data for 1987 from Gauge 141, located 30 m south of Gauge 111. In addition 

 Gauge 511 was used from January through October 1993. Multiple-year data 

 for Gauge 641 also include data from Gauge 645 (a Baylor staff gauge) which 

 was mounted at the same location as Gauge 641 from November 1984 until 

 May 1992, when it failed. 



Refraction, bottom friction, and wave breaking contribute to the observed 

 differences in height and period. During the most severe storms when the 

 wave heights exceed 3 m at the seaward end of the pier, the surf zone (wave 

 breaking) has been observed to extend past the end of the pier and occasion- 

 ally 1 km offshore. This occurrence is a major reason for the differences in 

 the distributions between Gauge 630 and the inshore gauges. The wave height 

 statistics for the pressure gauge (Gauge 641), located at the landward end of 

 the pier, were considerably lower than those for the other gauges. In all but 

 the calmest conditions, this gauge is within the breaker zone. Consequently, 

 these statistics represent a lower energy wave climate. 



1 M. E. Andrews. 1987. "Standard wave data analysis procedures for coastal engineering 

 applications," unpublished report prepared for U.S. Army Engineer Waterways Experiment 

 Station, Vicksburg, MS. 



22 



Chapter 3 Waves 



