The growth of fetch limited waves in water of finite depth. Part 1. Total energy and peak frequency

Abstract

The results of a fetch limited wind wave growth experiment in water of finite depth are presented. The experiment involved measurements of wind wave spectra, wind speed and direction at eight stations along the fetch. The site for the experiment was a lake with an almost constant water depth of 2 m. The results clearly show the evolution of both the non-dimensional total energy and peak frequency as a function of non-dimensional fetch. At short fetch, the waves are in deep water and the results are comparable to previous deep water measurements. As the fetch increases, the results diverge from the deep water case. Both the growth of total energy and the migration of the peak frequency to lower values are reduced in comparison to results from deep water conditions. At large fetch, evolution of both total energy and peak frequency ceases, both parameters becoming depth limited. Rather than there being a single growth law formula, as in deep water, a family of curves are developed, one for each value of non-dimensional depth.