Wind wave prediction in shallow water: Theory and applications

TLDR

The study presents a wind wave forecasting model based on the ray technique, tailored for shallow water regions. The model incorporates wave generation, refraction, shoaling, and parametrized nonlinear dissipation, delivering a directional spectrum from which the one‑dimensional spectrum and significant wave height are derived. Hindcasts of storms in the Northern Adriatic and Tyrrhenian Seas showed 10–20 % rms error in significant wave height, but highlighted a major issue in accurately evaluating the wind field.

Abstract

A wind wave forecasting model is described, based upon the ray technique, which is specifically designed for shallow water areas. The model explicitly includes wave generation, refraction, and shoaling, while nonlinear dissipative processes (breaking and bottom friction) are introduced through a suitable parametrization. The forecast is provided at a specified time and target position, in terms of a directional spectrum, from which the one‐dimensional spectrum and the significant wave height are derived. The model has been used to hindcast storms both in shallow water (Northern Adriatic Sea) and in deep water conditions (Tyrrhenian Sea). The results have been compared with local measurements, and the rms error for the significant wave height is between 10 and 20%. A major problem has been found in the correct evaluation of the wind field.