nonlinear wave interactions from the frequency band 0.35 -1.0 Hz to frequency bands 

 /< 0.35 Hz and/ > 1.0 Hz. Figures A. 1 1, A. 12, A. 14, and A. 15, for the larger wave 

 heights, show a similar transfer of energy but also show a decrease in peak wave energy 

 due to wave breaking. It is clear from these figures that the wave energy decrease due to 

 wave breaking increased dramatically as the generated wave energy increased. It is also 

 interesting that the measured reflected wave energy was much higher nearshore than 

 offshore. This trend is primarily because wave breaking and bottom friction reduce the 

 incident wave energy as waves progress shoreward while the reflected waves undergo 

 little energy change as they progress offshore. This is consistent with the measured 

 cross-shore variations of wave reflection from beaches (Baquerizo et al. 1997). 



Tables 4.3 and 4.4 list nearshore incident-wave characteristics for the six 

 wave trains, each of 15-min duration, measured with the structure in place. Table 4.3 

 lists the spectral analysis parameters, and Table 4.4 lists the time series parameters, both 

 at the location of the shallowest gage that was 0.91 m seaward of the toe. The values 

 were computed using the analysis method discussed above with the three nearshore 

 gages. In Table 4.3, the mean period T^ is defined by the relation 



. lfSrif)df 

 — = ^ (4.8) 







where S^{j) is the energy spectral density of the incident wave and /is the frequency. 



The spectral significant wave height is defined here as //„„ = 4m„"^ with m = zero 



67 



