An experimental study of alluvial channel response to large woody debris

176 Pages·1999·6.3 MB·English

by  Wallerstein, N. P

Historic, Archive Document
Do not assume content reflects current
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aTC529 R47
USDA Department of
United States Agricultural
Geography
Department of Research
Nottingham University
Agriculture Service
United Kingdom
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Channel & Watershed Processes Research Unit 0
National Sedimentation Laboratory ^
Oxford, Mississippi 38655
An Experimental Study of Alluvial Channel Response
to Large Woody Debris
By N.P. Wallerstein, C.V. Alonso, S.J. Bennett & C.R. Thorne
Research Report No. 10 January 1999
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jO r\ A Department of
I United States Agricultural
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Department of Research
Nottingham University
Agrieulture Service
United Kingdom
Channel & Watershed Processes Research Unit
National Sedimentation Laboratory
Oxford, Mississippi 38655
An Experimental Study of Alluvial Channel Response
to Large Woody Debris
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By N.P. Wallerstein, C.V. Alonso, S.J. Bennett C.R. Thorne
Research Report No. 10 January 1999
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Table ofContents
Acknowiedgements iv
List ofFigures V
List ofTables vii
List ofPlates vii
Chapter Introduction
1 ;
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Chapter 2: Literature concerning the hydraulic impact of
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2.1 Effect of on stage/discharge relationships, the hydrograph
and flood frequency
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2.2 Modeling the impact of on flow afflux 3
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2.3 Effect of on channel roughness 6
2.4 Elume techniques 9
Chapter 3: Similarity in model scaling 10
3.1 Basic principles 10
3.2 Secondary scale ratios 12
3.3 Influence ofviscous forces 13
3.4 Scaling channel boundary resistance in fixed bed models 15
3.5 Scale distortion 17
3.6 Moveable bed models 18
Chapter 4: Abiaca Creek scaling method 21
Chapter 5: Flume design and construction 33
Chapter 6: Description offlume results 40
6.1 Introduction 40
6.2 Expansion offlume results to prototype dimensions 40
6.3 Limitations ofthe flume model 41
Chapter 7: Discussion ofResults 44
7.1 Drag coefficient calculations for simulated debris elements 44
7.2 Selection ofdrag coefficient values 48
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7.3 Estimation offriction factor due to 49
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7.4 Drag force on elements in the model 51
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7.5 Drag force on elements in the prototype 52
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7.6 Incident flow veloeity on elements in the model 55
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7.7 Incident flow velocity on elements in the prototype 56
7.8 Conclusions from the hydraulie data 57
7.9 Geomorphic results: Flume 58
7.10 Geomorphic Results: Prototype 66
Chapter 8: Conclusions 72
Appendix 74
References 75
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