Wave transformation for beach nourishment projects

Descriptions of refraction and shoaling for input to one-line planform models of beach nourishment response are discussed. Three equations for bulk longshore sediment transport rate are compared to a small-scale laboratory data set, using up to three different descriptions of wave transformation. A simple, analytical description of wave transformation is presented that is consistent with the accuracy of the available equations describing longshore sediment transport rate. The simple approach appears favorable when compared to more rigorous descriptions of wave transformation for a gross estimate of beach nourishment evolution on a shoreline that is initially relatively straight. A new governing equation and analytical solution for beachfill evolution, including the effects of project-induced wave transformation, are presented. The analytical solution may be used as a design aid to indicate the influence of beachfill parameters (depth to toe, taper length) on beachfill lifetime. (C) 1997 Elsevier Science B.V.