Response of braiding channel morphodynamics to peak discharge changes in the Upper Yellow River |
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| Authors: | Filip Schuurman Wanquan Ta Sander Post Marius Sokolewicz Marcela Busnelli Maarten Kleinhans |
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| Institution: | 1. Department of Rivers and Coasts, Royal HaskoningDHV, Amersfoort, The Netherlands;2. Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, China;3. Faculty of Geosciences, Department of Physical Geography, Utrecht University, Utrecht, The Netherlands |
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| Abstract: | The braiding intensity and dynamics in large braiding rivers are well known to depend on peak discharges, but the response in braiding and channel–floodplain transformations to changes in discharge regime are poorly known. This modelling study addresses the morphodynamic effects of increasing annual peak discharges in braiding rivers. The study site is a braiding reach of the Upper Yellow River. We estimated the effects on the larger‐scale channel pattern, and on the smaller‐scale bars, channel branches and floodplains. Furthermore, we determined the sensitivity of the channel pattern to model input parameters. The results showed that the dominant effect of a higher peak discharge is the development of chute channels on the floodplains, formed by connecting head‐cut channels and avulsive channels. Widening of the main channel by bank erosion was found to be less dominant. In addition, sedimentation on the bars and floodplains increased with increasing peak discharge. The model results also showed that the modelled channel pattern is especially sensitive to parametrization of the bed slope effect, whereas the effect of median grain size was found to be relatively small. Copyright © 2018 John Wiley & Sons, Ltd. |
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| Keywords: | Yellow River discharge regulation Delft3D braiding floodplain |
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