Print Email Facebook Twitter Morphodynamic assessment of side channel systems using a simple one-dimensional bifurcation model and a comparison with aerial images Title Morphodynamic assessment of side channel systems using a simple one-dimensional bifurcation model and a comparison with aerial images Author van Denderen, R. Pepijn (University of Twente) Schielen, R.M.J. (Rijkswaterstaat) Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering) Hulscher, Suzanne J.M.H. (University of Twente) Kleinhans, Maarten G. (Universiteit Utrecht) Date 2017 Abstract Side channel construction is a common intervention applied to increase a river's conveyance capacity and to increase its ecological value. Past modelling efforts suggest two mechanisms affecting the morphodynamic change of a side channel: (1) a difference in channel slope between the side channel and the main channel and (2) bend flow just upstream of the bifurcation. The objective of this paper was to assess the conditions under which side channels generally aggrade or degrade and to assess the characteristic timescales of the associated morphological change. We use a one-dimensional bifurcation model to predict the development of side channel systems and the characteristic timescale for a wide range of conditions. We then compare these results to multitemporal aerial images of four side channel systems. We consider the following mechanisms at the bifurcation to be important for side channel development: sediment diversion due to the bifurcation angle, sediment diversion due to the transverse bed slope, partitioning of suspended load, mixed sediment processes such as sorting at the bifurcation, bank erosion, deposition due to vegetation, and floodplain sedimentation. There are limitations to using a one-dimensional numerical model as it can only account for these mechanisms in a parametrized manner, but the model reproduces general behaviour of the natural side channels until floodplain-forming processes become important. The main result is a set of stability diagrams with key model parameters that can be used to assess the development of a side channel system and the associated timescale, which will aid in the future design and maintenance of side channel systems. Subject BifurcationMorphodynamic modellingRiver morphodynamicsSide channelStability To reference this document use: http://resolver.tudelft.nl/uuid:2a241638-6743-4885-ab2b-c3cd969c89b1 DOI https://doi.org/10.1002/esp.4267 ISSN 0197-9337 Source Earth Surface Processes and Landforms, 43 (2018) (6), 1169-1182 Part of collection Institutional Repository Document type journal article Rights © 2017 R. Pepijn van Denderen, R.M.J. Schielen, A. Blom, Suzanne J.M.H. Hulscher, Maarten G. Kleinhans Files PDF van_Denderen_et_al_2017_E ... dforms.pdf 1.94 MB Close viewer /islandora/object/uuid:2a241638-6743-4885-ab2b-c3cd969c89b1/datastream/OBJ/view