VALIDATION OF THE SEMI-EMPIRICAL
LONGSHORE CURRENT MODEL

D. Lundberg
K. T. Holland
J. Church
Naval Research Laboratory
Stennis Space Center, MS 39529-5004

Abstract

A previously developed semi-empirical longshore current model that does not rely upon bathymetry was tested to determine the validity of the model on both planar (Santa Barbara, CA) and barred beaches (DUCK94 experiment). The only inputs being wave breaker height, wave breaker angle, and surf zone width. The model was further evaluated to determine conditions under which it failed. The results indicate that the model can be generally applied without a detailed knowledge of the bathymetry. Under most environmental circumstances, the normalized average error was 14% - 22%. Based on the DUCK94 data set, the model did not perform as well when wind forcing was strong due to storm passage. It also performed poorly during conditions when the wave breaker height was large and the breaker angle was near zero. Nevertheless, 84% of the predictions had a normalized average error of 50% or less indicating the model is reasonably robust.

Sponsored by the Naval Research Laboratory.

Published on January 25, 1999.
Naval Research Laboratory Contribution Number NRL/MR/7442 98-8092.
NRL Memorandum Report