Wave energy dissipation by reef breakwaters

Shoreline erosion has become a chronic problem around much of the U.S. coast. Fulford (1985) has shown using segmented reef breakwaters is one of the most effective strategies for providing shore­ line protection. Reef breakwaters are essentially homogeneous piles of stone without the multi-layer cross sections of traditional breakwaters. The effectiveness of a reef is partly due to its ability to dissipate wave energy and additionally due to the bulk of the salient which accumulates behind the structure. Extensive laboratory model tests have been used to define performance characteristics of reefs. Results from these tests have been used to develop equations that predict wave transmission and reflection characteristics which can then be used to determine the ability of the structure to dissipate wave energy (Ahrens 1987b). The equations fit the data well, approach logical limiting values, are easy to use, and are consistent with the physics of the interaction between waves and rubble structures as it is currently understood.