Author(s): Sandra Prohaska; Bernhard Westrich
Linked Author(s): Bernhard Westrich
Keywords: Suspended sediment transport; Exchange; Groyne fields; Elbe; 1D modelling; Multistrip method
Abstract: Many European rivers have been trained and regulated by different structures along the banks, which greatly influence the flow field and transport of sediments. In the past a great amount of sediments associated with contaminants were deposited in those low flow near bank water bodies. In recent years emission of contaminants is reduced and more clean sediments were deposited above contaminated ones. Therefore, contaminated sediments do not affect water quality directly. However, the deposited sediments present potential hazard and could be resuspended and remobilized by erosive flood events. This study aims at modelling long river sections trained by groynes. The exchange of water and suspended sediments between the main stream and adjacent stagnant water zone is the key process of sediment transport in such waterways. Therefore, interaction between the groyne fields and the main channel was modelled by one-dimensional multi-strip model, which enables water and mass exchange between adjacent strips. The model was applied on a simple prismatic channel in order to test the main processes and to explore the capacity and limitation of the model. Since the River Elbe is trained by groyne structures, the model was applied on 112 km long reach. A six days flood event was simulated by unsteady flow and transport calculation in order to determine the effect of the flood on the sediments deposited in groyne fields.
Year: 2007