Dissipation of Group Waves in Shallow Water for Wave Model Input

Surface wave data from sixteen different laboratory experiments using single and double peaked spectra was processed for wave energy spectra, shape, and dissipation parameters to describe the evolution of the double-peaked narrow-banded waves. Starting from a known model for random wave dissipation, the group waves were processed, and different regions of wave interactions were catalogued. The long wave segment of the wave groups was monitored since energy is not readily lost from long waves. The associated wave number spectra of mechanically created group waves was also determined and the corresponding wave number dependence of the spectral density compared to two theoretical values: that for the Zakharov range (2.5kvp ≤ k ≤ 1/h ) and for the Toba range (k > 1/h). This comparison to these formulations for broadbanded spectra reveals whether narrow-banded wave groups can be similarly described. A time-varying dissipation mechanism was used to deduce the instantaneous energy loss from breaking; these events will also be analyzed via a probability density function and used to better model narrow-banded wave dissipation in shallow water. The trend of the most probable dissipation event was also calculated and compared to the depth. Trends of dissipation were correlated to that of the related wave energy spectra. The dependence of dissipation on higher frequencies was evaluated. The result will be useful to catalogue the dissipation of group waves