scholarly journals Development of ST:REAM: a reach-based stream power balance approach for predicting alluvial river channel adjustment

2014 ◽  
Vol 40 (3) ◽  
pp. 403-413 ◽  
Author(s):  
Chris Parker ◽  
Colin R Thorne ◽  
Nicholas J Clifford
Keyword(s):  
River Channel ◽  
Power Balance ◽  
Stream Power ◽  
Channel Adjustment ◽  
Alluvial River ◽  
Balance Approach

Minimum stream power and river channel patterns

1979 ◽  
Vol 41 (3-4) ◽  
pp. 303-327 ◽  
Author(s):  
Howard H. Chang
Keyword(s):  
River Channel ◽  
Stream Power ◽  
Channel Patterns

River channel adjustment of several river reaches on Ebro basin

2015 ◽  
Vol 364 ◽  
pp. 44-53 ◽  
Author(s):  
Pedro Besné ◽  
Askoa Ibisate
Keyword(s):  
River Channel ◽  
Ebro Basin ◽  
Channel Adjustment

Reservoir effects on downstream river channel migration

2000 ◽  
Vol 27 (1) ◽  
pp. 54-66 ◽  
Author(s):  
F. DOUGLAS SHIELDS JR ◽  
ANDREW SIMON ◽  
LYLE J. STEFFEN
Keyword(s):  
Flood Control ◽  
Habitat Type ◽  
River Channel ◽  
Aerial Photographs ◽  
Lateral Migration ◽  
Widespread Application ◽  
Ecosystem Integrity ◽  
Migration Rates ◽  
Alluvial River ◽  
River Floodplains

Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr-1 to 1.8 m yr-1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.

Modelling landslide-flood interactions: an example from Colorado

2021 ◽  
Author(s):  
Diego Panici ◽  
Georgie Bennett
Keyword(s):  
Limited Range ◽  
River Channel ◽  
Natural Phenomenon ◽  
Model Parameters ◽  
River Channels ◽  
Stream Power ◽  
Two Phase ◽  
The North ◽  
Channel Blockage ◽  
Deposition Processes

<p>Landslides and debris flows represent natural phenomenon with high geomorphic impact and of significant cascading hazards to human lives and built environment. Intense rainfall events are key triggers of landslides and, as a result, landslides end up interacting with river channels during floods. Large masses of sediment can overwhelm the sediment transport capacity of a river channel and result in the formation of a dam. Nevertheless, this build-up process is not always evident in the aftermath of the event: when a dam burst occurs, a surge of mixed solid and fluid material is produced resulting in significant erosion in the downstream channel. Eventually, the blockage is removed, leaving the process of dam build-up and bursting undocumented. Due to the abrupt nature of this phenomenon, field observations are difficult to obtain.</p><p>In this study, we carried out a preliminary analysis by using a computational model to replicate the formation of a channel blockage downstream of a series of landslides during an event that occurred in the North St Vrain Creek in Colorado, USA, during the Great Colorado Storm in September 2013 (estimated to be a 1 in 1000 years event). In this case, there is limited documented evidence of a blockage, but a dam and its busting were hypothesised by analysing very large erosional patterns in a downstream reach that could not be explained by typical erosive processes (e.g. stream power). We employed the free source code r.avaflow, which is a two-phase model. This code can simulate complex chain phenomena, rapid routing mass flows, and entrainment-deposition processes. Topography of the area was obtained by using high resolution LiDAR DEM before and after the flood event in 2013 and was used as basal topography for simulations, as well as to estimate the amount of sediment released by the landslides. The flood flow employed for the simulation was based on estimated rainfall-runoff and kept constant, since the total simulation time was small compared to the actual flood curve duration. We also tested a limited range of parameters to account for the inherent uncertainties in the variables used.</p><p>The model was able to represent the erosion from the landslides and on the river channel, but also displayed the formation of a dam downstream of the landslides across all simulations. Although the topographic change and volume of mobilised sediments were affected by the variation of the model parameters, the formation of the channel blockage was always observed. This modelling will provide the basis for further modelling on landslide-channel interactions and will explain those phenomena that have only been postulated but not directly observed.</p>

scholarly journals Changes in floodplain inundation under nonstationary hydrology for an adjustable, alluvial river channel

2017 ◽  
Vol 53 (5) ◽  
pp. 3811-3834 ◽  
Author(s):  
B. C. Call ◽  
P. Belmont ◽  
J. C. Schmidt ◽  
P. R. Wilcock
Keyword(s):  
River Channel ◽  
Alluvial River ◽  
Floodplain Inundation
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