Macroroughness and variations in reach-averaged flow resistance in steep mountain streams

Flow in rough steep open channels is mostly found in mountain streams and in flow overtopping protected weirs. In both cases, the energy of the flowing stream may be dissipated by artificial means so that the flowing water does not result in serious damage due to scour or erosion downstream of the main slope. The best way of achieving this purpose is to lead the flow over a series of steps. In this investigation, the author tried to determine the form drag of stepped steep open channels, considering the steps as two-dimensional triangular roughness elements. Key words: open channel flow, flow resistance, channel roughness, form drag, steep channels.

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Quantifying flow resistance in mountain streams using computational fluid dynamics modeling over structure‐from‐motion photogrammetry‐derived microtopography

Earth Surface Processes and Landforms ◽

10.1002/esp.4624 ◽

2019 ◽

Vol 44 (10) ◽

pp. 1973-1987 ◽

Cited By ~ 1

Author(s):

Yunxiang Chen ◽

Roman A. DiBiase ◽

Nicholas McCarroll ◽

Xiaofeng Liu

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Structure From Motion ◽

Flow Resistance ◽

Mountain Streams ◽

Dynamics Modeling ◽

Computational Fluid Dynamics Modeling

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Evaluation of bedload transport predictions using flow resistance equations to account for macro-roughness in steep mountain streams

Water Resources Research ◽

10.1029/2011wr010645 ◽

2011 ◽

Vol 47 (8) ◽

Cited By ~ 89

Author(s):

Manuel Nitsche ◽

Dieter Rickenmann ◽

Jens M. Turowski ◽

Alexandre Badoux ◽

James W. Kirchner

Keyword(s):

Flow Resistance ◽

Bedload Transport ◽

Mountain Streams

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Controls on spatial variations in flow resistance along steep mountain streams

Water Resources Research ◽

10.1029/2009wr008134 ◽

2010 ◽

Vol 46 (3) ◽

Cited By ~ 41

Author(s):

Gabrielle C. L. David ◽

Ellen Wohl ◽

Steven E. Yochum ◽

Brian P. Bledsoe

Keyword(s):

Flow Resistance ◽

Spatial Variations ◽

Mountain Streams

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New Flow-Resistance Law for Steep Mountain Streams Based on Velocity Profile

Journal of Irrigation and Drainage Engineering ◽

10.1061/(asce)ir.1943-4774.0001208 ◽

2017 ◽

Vol 143 (8) ◽

pp. 04017024 ◽

Cited By ~ 8

Author(s):

Vito Ferro

Keyword(s):

Velocity Profile ◽

Flow Resistance ◽

Mountain Streams

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Review of step-pool hydrodynamics in mountain streams

Progress in Physical Geography Earth and Environment ◽

10.1177/0309133319859807 ◽

2019 ◽

Vol 43 (5) ◽

pp. 607-626

Author(s):

Sruthi Thazhathe Kalathil ◽

Venu Chandra

Keyword(s):

Flow Resistance ◽

Model Development ◽

Flow Analysis ◽

Air Entrainment ◽

Mountain Streams ◽

Laboratory Studies ◽

Flow Conditions ◽

Total Flow ◽

Flow Phenomenon ◽

Design Considerations

Step-pools are one of the major types of bed morphology prevalent in mountain streams. They have a unique flow structure as compared to low-gradient streams, in terms of large boundary elements and alternating super-critical and sub-critical flow conditions, which result in a non-uniform flow regime. Step-pools may also be constructed artificially to restore mountain incisions, and for creating close-to-nature fish passes. For hydraulic model development and various design considerations, the accurate prediction of flow phenomenon is required. This necessitates a detailed study of the turbulence phenomenon in natural step-pool reaches and its effect on the total flow. However, the influence of aerated conditions in step-pool hydrodynamics has not yet been adequately addressed. This paper presents a review of the mechanism of flow resistance and energy dissipation in step-pool mountain streams. Also, the significance of incorporating air entrainment in flow analysis, limitations and the way forward in modeling air–water flow in laboratory studies are discussed.

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