Title
How Does a River Bifurcation System Respond to Peak Flows? A Case Study of the Upper Dutch Rhine Bifurcation Region
Author
Chowdhury, M. Kifayath (TU Delft Rivers, Ports, Waterways and Dredging Engineering) 
Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)
Ylla Arbos, C. (TU Delft Rivers, Ports, Waterways and Dredging Engineering)
Verbeek, Merel C. (Rijkswaterstaat)
Schropp, Max H.I. (Rijkswaterstaat)
Schielen, R.M.J. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Rijkswaterstaat)
Date
2022
Abstract
Sediment transport capacity and supply of sediment to a river channel increase significantly during peak flow events. Here we study how a river bifurcation system (partitioning water and sediment over its downstream branches) responds to peak flow events. We focus on the Pannerdense Kop bifurcation in the Dutch Rhine River, an engineered system where planform and channel width are fixed. We analyze water discharge and bed level data measured over the last century. We observe rapid aggradation in one of the branches (Pannerden Channel) following the peak flow events of 1993 and 1995, and little to no bed level change in the other branch (Waal). Prior to the event, both branches eroded, and the upstream part of the Pannerden Channel had a greater erosion rate than the Waal. After the 1993 and 1995 peak flow events, the erosion in the upstream part of the Pannerden Channel slowed significantly, whereas the upstream part of the Waal branch continued to erode (though at a smaller pace than before the peak flow events). This differential erosion has resulted in a gradual increase of water discharge toward the Waal branch. Interestingly, the bifurcation system does not appear to respond equally to all peak flow events. We hypothesize that the bifurcation response to the 1993 and 1995 peak flows differs from previous peak flows because of the sequence of the two events. Between the 1993 and 1995 events, the system may not have had sufficient time to disperse the sediment deposited at the upstream end of the Pannerden channel. Another reason for the response to the 1993 and 1995 peak flows to differ from previous events may be that the channel bed surface within the region of interest has coarsened significantly. This study illustrates the importance of peak flows regarding bifurcation dynamics, and further research is focused on the interaction between bifurcation dynamics and the dynamics of the larger-scale system.
Subject
River bifurcation
Pannerdense Kop
Peak flow
Rhine River
Dutch Rhine
To reference this document use:
http://resolver.tudelft.nl/uuid:8f93b028-7b3e-432e-ae99-021c911272a3
Embargo date
2023-06-16
Event
AGU Fall Meeting 2022, 2022-12-12 → 2022-12-16, Chicago, United States
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
abstract
Rights
© 2022 M. Kifayath Chowdhury, A. Blom, C. Ylla Arbos, Merel C. Verbeek, Max H.I. Schropp, R.M.J. Schielen