Variable input parameter influence on river corridor prediction

This paper considers the erodible river corridor, which is the area in which the main river channel is free to migrate over a period of time. Due to growing anthropogenic pressure, predicting the corridor width has become increasingly important for the planning of development along rivers. Several approaches can be used to predict the future...

Modelling of sedimentation processes inside Roseires Reservoir (Sudan)

Roseires Reservoir, located on the Blue Nile River in Sudan, is the first trap to the sediments coming from the vast upper river catchment in Ethiopia, which suffers from high erosion and desertification problems. The reservoir has already lost more than one-third of its storage capacity due to sedimentation in the last four decades. Appropriate...

Modelling of sedimentation processes inside Roseires Reservoir (Sudan) (discussion)

Discussion paper. Roseires Reservoir, located on the Blue Nile River, in Sudan, is the first trap to the sediments coming from the upper catchment in Ethiopia, which suffers from high erosion and desertification problems. The reservoir lost already more than one third of its 5 storage capacity due to sedimentation in the last four decades....

Effect of the barrage and embankments on flooding and channel avulsion case study Koshi River, Nepal

Humans have utilized water resources for millennia by modifying natural river courses and such interventions have greatly influenced not only river flows and sediment fluxes, but also the overall river morphology. Situated in the Nepal's eastern Ganges region, the braided Koshi River is unique among the other rivers, because of the high...

Experimental and numerical findings on the long-term evolution of migrating alternate bars in alluvial channels

Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether migrating bars eventually reach a (dynamic) equilibrium, as in previous...

Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels

Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels

Alternate bars in straight alluvial channels are migrating or nonmigrating. The currently accepted view is that they are nonmigrating if the width-to-depth ratio is at the value of resonance or if the bars are forced by a persistent local perturbation. We carried out 2-D numerical computations and a long-duration mobile-bed flume experiment to...

Effects of river floodplain lowering and vegetation cover

The current river management policy in the Netherlands is to give rivers more space, mainly by main channel widening and floodplain lowering. The aim is to reduce flood water levels and to create more favourable conditions for river ecology. However, the effect on water levels gradually disappears due to sedimentation and vegetation growth on...

Simple physics-based predictor for the number of river bars and the transition between meandering and braiding

The number of bars that form in an alluvial channel cross section can be determined from a physics-based linear model for alluvial bed topography. The classical approach defines separators between ranges in which river planform styles with certain numbers of bars are linearly stable and linearly unstable. We propose an alternative method that is...

Effects of smoothing and regridding in numerical meander migration models

Meander migration models include an as yet poorly investigated source of numerical errors related to the computation of the channel curvature, which are amplified by the procedure of adding and deleting grid points as the river planform evolves. The methods adopted to reduce these errors may influence size, form, and migration rate of the...