Open AccessCARIBBEAN BEACH-FACE SLOPES AND BEACH EQUILIBRIUM PROFILES
Author(s) -
John D. Boon,
Malcolm O. Green
Publication year - 1988
Publication title -
proceedings of conference on coastal engineering/proceedings of ... conference on coastal engineering
Language(s) - English
Resource type - Journals
eISSN - 2156-1028
pISSN - 0589-087X
DOI - 10.9753/icce.v21.120
Subject(s) - geology , submarine pipeline , curvature , sediment , geomorphology , deposition (geology) , plage , geometry , oceanography , mathematics , shore
Field measurements performed on two Caribbean islands revealed that two-dimensional nearshore bottom morphology is well represented by Dean's (1977) model of the beach equilibrium profile, h - A xm, where h is depth below mean water level at a distance x offshore and A is a scale factor. For the curvature, m, we obtained an average value of approximately m - 1/2 through least squares curve fitting of observed profile data, yielding a more concave and therefore steeper profile inshore than m — 2/3, the average previously reported by Dean for quartz sand beaches in the United States. Furthermore, an objective measure of beach steepness was found to be A-*-'1", a quantity which utilizes both of Dean's parameters and which may serve as a surrogate for the beach-face slope, tan /3, on highly concave beaches. Reasonable correlations were found between A?-'m and the environmental parameter, H^ /gDT , where H^ is breaker height, D is sediment grain size, T is wave period and g is gravitational acceleration. Improved prediction of Caribbean beach slopes and beach equilibrium profiles is an important practical result.