• rip currents;
  • nearshore morphology;
  • trend-surface analysis;
  • morphometry


A major problem facing coastal nearshore studies is the conversion of survey data to precise two- and three-dimensional representations of complex surf zone topography. In addition to inherent problems in providing accurate survey data, most significant topographical boundaries are often delineated in a subjective manner. A trend-surface technique is hereby presented which provides an objective, rigorous, and replicable method of identifying morphological rip system channel boundaries in the surf zone. Using an extensive field dataset obtained over two field experiments, including an almost complete cycle of low-energy intermediate beach state evolution, this technique is shown to produce accurate planimetric dimensions for a range of topographic beach state morphologies. Previously absent or highly descriptive in the literature, formal morphometric definitions of geometric dimensions for rip morphologies, including rip-channel width, relief, depth, and cross-sectional areas, are provided. Several new aspects of rip-current morphology are discussed from results of the approach. The approach described here is also intended to illustrate the potential for future trend-surface applications to surf zone and other geomorphological studies. Copyright © 2003 John Wiley & Sons, Ltd.