Author(s): A. M. Ferreira Da Silva; Y. Zhang
Keywords: Lluvial streams; Sand dunes; Dune steepness; Friction factor; Flow depth
Abstract: The present paper concerns the determination of dune geometry and friction factor of flow over a sand-bed covered by dunes. An expression for dune steepness is introduced. This expression is a modified version of the dune steepness expression of Yalin and Karahan. The modification (which is based on recent research on dune geometry by Julien and Klaassen) extends the applicability of the original expression in Ref. to a wider range of values of relative roughness (in particular, to the range of values typical of large rivers). In order to test the validity of the present dune steepness expression, values of computed flow depth are compared with their measured counterparts for all the laboratory and field data available to the authors.