Print Email Facebook Twitter A coupled numerical solution to the shallow water-Hirano model (abstract) Title A coupled numerical solution to the shallow water-Hirano model (abstract) Author Stecca, G. Blom, A. Faculty Civil Engineering and Geosciences Department Hydraulic Engineering Date 2013-06-09 Abstract Modelling the morphodynamic evolution of rivers due to flow-driven sediment transport requires the adoption of a flow model, such as the shallow water equations, and a conservation equation for sediment mass (the Exner equation). When dealing with mixtures of grain sizes, one can account for the interaction among sediment transport, bed level variation and development of bed stratigraphy using a grainsize-specific form of the sediment conservation equation. Hirano (1971) was the first to develop such a continuity model. He introduced a sediment exchange layer (the "active layer") providing a source of sediments to be entrained in the flow and regulating the exchange with the substrate layer located underneath. The active layer model requires a closure relation for the (time varying) active layer thickness. The classical approach is to assume for it a constant value, which deeply affects the celerity of sorting waves (Ribberink, 1987). A preferable approach, however, is to link its value to physical properties of the river bed, such as some reference sediment diameter in the plane bed case or the dune height in the bedform-dominated case (e.g. Ribberink (1987)). To reference this document use: http://resolver.tudelft.nl/uuid:9a45420c-ad04-46d3-ae72-7efe3724b394 Publisher IAHR ISBN 978-7-89444-548-3 Source RCEM 2013: 8th Symposium on River, Coastal and Estuarine Morphodynamics, Santander, Spain, 9-13 June 2013 Part of collection Institutional Repository Document type conference paper Rights (c) 2013 The Author(s) Files PDF 293594.pdf 61.94 KB Close viewer /islandora/object/uuid:9a45420c-ad04-46d3-ae72-7efe3724b394/datastream/OBJ/view