REVISED WAVE FORECASTING RELATIONSHIPS

C L Bretschneider

doi:10.9753/icce.v2.1

Abstract

Data on the generation and decay of wind-generated gravity waves have been collected for several years by the University of California. These data together with the original data by Sverdrup and Munk have been analyzed, and the results were presented in dimensionless graphs suitable for use in wave forecasting (Bretschneider, 1951). No analysis was made of the effect of following or opposing winds.

Highlights

Data on the generation and decay of wind-generated gravity waves have been collected for several years by the University of California
Using D/F as a dimensionless parameter, decay graphs, D/gTp2 versus D/gTp2 and D/Hp versi D/HD, were constructed representing the increase of period and the decreas in height, respectively. These curves give a unique solution for each combination of period and height at the end of the fetch; whereas, the decay relationships proposed by Sverdrup and Munk (1947) gave a unique solution for the increase of wave period regardless of the wave height at the end of the fetch
To determine the wave height, HQ at the end of the decay curves, use Figure 3-C and D,' and read Hp/Hp

Summary

Introduction

It is found that the wave height and period at the end of the decay distance depend upon the length of the fetch and the height and period at the end of the fetch as well as upon the decay distance. These curves give a unique solution for each combination of period and height at the end of the fetch; whereas, the decay relationships proposed by Sverdrup and Munk (1947) gave a unique solution for the increase of wave period regardless of the wave height at the end of the fetch.

Results

Conclusion