Mitigation of Channel Bed Erosion through Floodplain Lowering and Nourishments

Channel adjustment in engineered rivers is often associated with channel bed incision (e.g., Chowdhury et al., 2023, Czapiga et al., 2022a, 2022b, Ylla Arbós et al., 2021). Channel bed incision reduces the stability of in-river structures, exposes river-crossing cables and pipelines, and the spatial variability of channel bed incision due to less erodible reaches creates shipping bottlenecks.
Various measures have been implemented to cope with these issues. They range from sediment nourishments to erosion control structures (e.g., Habersack and Piégay, 2007). Our objective is to assess the potential of floodplain lowering and sediment nourishments in mitigating large-scale channel bed incision in engineered rivers affected by climate change, considering a spatial scale of hundreds of kilometres. Our domain of interest is the Rhine River between Bonn, Germany, to Gorinchem, Netherlands. This reach has been extensively channelized during the 18th-20th centuries for improved navigation and flood protection (e.g., Ylla Arbós et al., 2021).