THE GROWTH OF FETCH LIMITED WAVES IN WATER OF FINITE DEPTH .2. SPECTRAL EVOLUTION

Results showing the evolution of the wave spectrum in finite depth, fe tch limited conditions are presented. The data were obtained from a se ries of eight wave gauges established in shallow Lake George, Australi a, The data are well modelled by the previously proposed TMA spectral form and clearly show the transition of the spectra from deep water to depth limited conditions, The TMA parameter of alpha is found to be a function of the non-dimensional wavenumber, kappa but the spectral pe ak shape parameters of gamma and sigma appear uncorrelated with kappa. The parameter gamma is shown to be a function of both-nondimensional fetch, chi and non-dimensional depth, delta. In severely depth limited conditions gamma becomes solely a function of delta, increasing in ma gnitude as delta decreases. Hence, depth limited spectra could be expe cted to be very peaked compared to deep water counterparts.