Evaluating the Impact of Beach Nourishment on Surfing: Surf City, Long Beach Island, New Jersey, USA

摘要

Utilizing the Cornell University Long and Intermediate WAVE (COULWAVE) Boussinesq wave model, the effect of the construction of a conventional beach nourishment project in Surf City, New Jersey, on the quality of the local surf break is examined in detail. A 20-year-long nearshore synthetic wave record is first developed for use in creating a monthly wave climate "almanac'' so that typical seasonal effects on surf-break quality can be objectively portrayed. The wave model is then run with preconstruction bathymetric conditions, and with three postconstruction surveys performed in subsequent months. Construction of the nourishment project was found to affect the quality of the surf break adversely by (1) compression of the surf zone, (2) an increase in the occurrence of "closeouts,'' (3) a shift in breaker type toward collapsing breakers, particularly during high tide, and (4) an increase in wave reflection-findings that are in agreement with anecdotal testimony offered by local surfers. On the basis of modeling results conducted using the sequential postconstruction surveys and the wave almanac, it appears to have required nominally 21-22 months for the surf-break quality to return to preproject conditions. A paradigm shift in the design and construction of beach nourishment projects in the United States is required if such effects are to be avoided, and several options are offered and discussed.