EFFECTS OF NONUNIFORM WAVE ENERGY IN THE LITTORAL ZONE

[摘要] Bi-weekly monitoring of four closely-spaced permanent beach profile stations located on the northeast end of Monomoy Island (Cape Cod) has revealed major variations in the amount of erosion and accretion occurring along this portion of the Massachusetts shoreline During the 27-month monitoring period a close relationship was observed between changes in the beach and offshore portions of the profiles Three distinct types of bars were noted (1) Subtidal bars which are parallel to the shoreline and located one to two thousand feet off those portions of the shoreline undergoing relatively small amounts of beach erosion, (2) Subtidal bars which are perpendicular to the shoreline and attached to areas of the shore undergoing large amounts of erosion, and (3) Large intertidal bars which are oriented obliquely to the shoreline and associated with the formation of the ebb-tidal delta and the resulting wave refraction patterns The large variations in erosion and accretion occurring along the beach at any one time are related to the nonumform distribution of energy within the waves arriving at this section of the coastline This nonunifortuity of wave energy is attributed to refraction of the waves around the irregular bathymetry offshore from Monomoy, and it appears to produce shoreline protuberances of sand which are flanked updrift and downdrift by erosional zones.

[学科分类] 建筑学

[关键词] nonuniform waves;wave energy;littoral zone