Author(s): Andrea Marion; Ian Mcew An; Simon Tait

Linked Author(s): Andrea Marion, Simon Tait

Keywords: No Keywords

Abstract: Two experiments are reported which were carried out in a laboratory flume with a compound cross-section. A steady water discharge was applied in both runs. Bankfull and overbank flows were studied. Both runs were carried out under zero sediment feed conditions. The runs were terminated when the sediment transport measured at the downstream end of the flume was negligibly small. The surface bed composition at the final equilibrium state was measured using a wax sampling technique. The physical texture of the bed was also measured by measuring bed surface elevation distributions at a grain scale. While it was observed that the surface compositions did not change significantly from the initial conditions, results from texturing indicated a significant change in the probability distributions of the surface elevations in each experiment. The combination of the two sets of results shows that, in the considered cases, the stabilization of the bed was achieved mainly by a stable re-arrangement of the surface grains, rather than by vertical size sorting of the bed material. It was therefore believed that particle arrangement may play a significant role in the

DOI:

Year: 1997