Sediment flux‐driven channel geometry adjustment of bedrock and mixed gravel–bedrock rivers
نویسندگان
چکیده
منابع مشابه
Sediment supply controls equilibrium channel geometry in gravel rivers.
In many gravel-bedded rivers, floods that fill the channel banks create just enough shear stress to move the median-sized gravel particles on the bed surface (D50). Because this observation is common and is supported by theory, the coincidence of bankfull flow and the incipient motion of D50 has become a commonly used assumption. However, not all natural gravel channels actually conform to this...
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[1] Bedrock erosion in mountain river channels ultimately sets the erosion rate of the surrounding hillslopes and the rate of sediment supply to the channels. The supply of coarse bed sediment acts as a dampening effect on further erosion by depositing an alluvial cover that temporarily obscures the bedrock. For landscapes where the residence time of the alluvial bed cover is comparable to the ...
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In this study, the distribution of channel-bed sediment facies in the lowermost Mississippi River is analysed using multibeam data, complemented by sidescan sonar and compressed high-intensity radar pulse seismic data, as well as grab and core samples of bed material. The channel bed is composed of a discontinuous layer of alluvial sediment and a relict substratum that is exposed on the channel...
متن کاملControls on the channel width of rivers: Implications for modeling fluvial incision of bedrock
On the basis of the Manning equation and basic mass conservation principles, we derive an expression for scaling the steadystate width (W) of river channels as a function of discharge (Q), channel slope (S), roughness (n), and width-to-depth ratio (!): W " [!(! # 2)2/3]3/8Q3/8S$3/16n3/8. We propose that channel width-todepth ratio, in addition to roughness, is a function of the material in whic...
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ژورنال
عنوان ژورنال: Earth Surface Processes and Landforms
سال: 2020
ISSN: 0197-9337,1096-9837
DOI: 10.1002/esp.4996