Morphodynamic assessment of side channel systems using a simple one-dimensional bifurcation model and a comparison with aerial images

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...

Sediment Transport of Fine Sand to Fine Gravel on Transverse Bed Slopes in Rotating Annular Flume Experiments

Large-scale morphology, in particular meander bend depth, bar dimensions, and bifurcation dynamics, are greatly affected by the deflection of sediment transport on transverse bed slopes due to gravity and by secondary flows. Overestimating the transverse bed slope effect in morphodynamic models leads to flattening of the morphology, while...

Bank erosion processes measured with UAV-SfM along complex banklines of a straight mid-sized river reach

We apply structure from motion (SfM) photogrammetry with imagery from an unmanned aerial vehicle (UAV) to measure bank erosion processes along a mid-sized river reach. This technique offers a unique set of characteristics compared to previously used methods to monitor banks, such as high resolution and relatively fast deployment in the field....

Distinct patterns of bank erosion in a navigable regulated river

Distinct bankline patterns appeared after the removal of protection works along a navigable reach of the Meuse River. A series of oblique embayments now dominate the riverine landscape after ten years of bank erosion, but their location and asymmetry cannot be explained yet. This work analyses and integrates field measurements of flow, ship...

A characterization of side channel development

Side channels are commonly constructed to reduce the flood risk or to increase the ecological value of a river. Such artificial side channels generally aggrade. We categorize the development of side channels based on the sediment that is deposited in these channels. Based on this categorization, we determine the main mechanisms that affect their...

Erosion processes and retreat prediction of re-naturalized banks in regulated navigable rivers

Self-constraining of low-energy rivers explains low channel mobility and tortuous planforms

Meandering rivers are abundant on Earth, from the largest rivers to the smallest tributaries. The classical view of meandering rivers is a sinuous planform with rounded bends, which grow and migrate until they are cut-off. However, many low-energy meandering rivers have planforms that are much more complex than this classical view due to the...

Mangrove forests as a nature-based solution for coastal flood protection: Biophysical and ecological considerations

Nature-based coastal protection is increasingly recognised as a potentially sustainable and cost-effective solution to reduce coastal flood risk. It uses coastal ecosystems such as mangrove forests to create resilient designs for coastal flood protection. However, to use mangroves effectively as a nature-based measure for flood risk reduction...

Floodplain Connecting Channels as Critical Paths for Hydrological Connectivity of Deltaic River Networks

A river bifurcation is critical for distributing water, sediment and nutrients to the downstream branches of deltaic river networks. However, the downstream branches of a bifurcation can be linked by a connecting channel cutting through deltaic floodplains. The floodplain connecting channel as a downstream control can affect water...

The Contribution of Sand Ripple and Slope Driven Sediment Flux to Morphologic Change of an Idealized Mound Under Waves

We investigate pathways of sediment diffusion for a Gaussian-shaped sand mound subjected to monochromatic waves. Our unique results nearly close the sediment budget by quantifying each of the sediment transport processes responsible for mound diffusion associated with sediment flux due to slope driven transport and ripple migration. Downslope...