Laboratory Study of Wave‐Breaking over Bars and Artificial Reefs

Abstract

One‐hundred eight regular‐wave tests and 12 random‐wave tests were performed in a tank to investigate properties of waves breaking on irregular beach profiles. In the tests, solid objects representing natural barred profiles, terraced profiles, and artificial reefs were installed on a concrete slope of 1/30. Wave conditions covered deep‐water steepnesses from 0.0085 to 0.09. A large data base of previous measurements of wave breaking on plane slopes was also compiled and analyzed for comparison to the barred profile measurements. Significant differences were found in such properties as breaker type, breaker depth and height indices, plunge distance, and splash distance for plane and barred slopes. The ratio of wave height and water depth of random waves transforming over a bar was not constant, as previously reported from field measurements, but showed a bimodal distribution with maxima of approximately unity at the bar crest and foreshore and minima of approximately 0.45 in the offshore and bar trough.