BEDFORMS AND UNDERTOW IN THE SURF ZONE
ABSTRACT
The present report gives the results of a study on bedforms and undertow in the surf zone.Itis the objective of this study to get a better insight into the physical processes in the surf zone.Inthis study, we make use of the data obtained during the LIP llD-experiments (Arcillaet al. [1994] and Roelvink and Reniers [1994]).
We derive the characteristics of bedforms from measured profiles. We relate these bedform characteristics to the hydraulic conditions and analyse if they can be predicted with present prediction methods.
Further, we develop an inverse modelling technique, which is based on the mass and momentum balance equations. With this technique we derive values of important physical parameters, like eddy viscosity, shear stresses, friction factors, bed roughness and mass flux.
The derived physical parameters are compared with present methods to describe these parameters. .
ACKNOWLEDGEMENTS
The present study is part of the Ph.D work of the author at the Department of Civil Engineering of Delft University of Technology. This work is carried out as a part of a research project on the modelling of the hydrodynamics and sediment transport distribution over a beach profile under wave action.
The present study uses data, which were measured during the LIP llD-experiments, which were carried out in the Delta Flume of Delft Hydraulics in 1993. LIP stands for the Large Installation Plan, a program sponsored by the European Union.
The author thanks Dr. l van de Graaff and Dr. J.A. Roelvink for their critical comments on this report. Further, the author thanks Dr. lA. Roelvink andMr. A.J.H.M. Reniers for making the LIP llD-data available.
