producing a frequency band width of 0.01 17 Hz). 



Wave period Tp 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., Tj, = 1 /frequency) of the spectral band with the 

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

 in an impublished report by Andrews (1987).' 



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 com- 

 bined 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 

 previously located at the approximate depth and distance offshore of Gauge 

 1 1 1) and data for 1987 from Gauge 141 , located 30 m south of Gauge HI. 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 

 occasionally 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. 



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 applications, " unpublished report prepared for U.S. Army Engineer Waterways Experiment 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



