Gravel-Bed Rivers

With contributions from key researchers across the globe, and edited by internationally recognized leading academics, Gravel-bed Rivers: Processes and Disasters presents the definitive review of current knowledge of gravel-bed rivers. Continuing an established and successful series of scholarly reports, this book consists of the papers presented at the 8th International Gravel-bed Rivers Workshop. Focusing on all the recent progress that has been made in the field, subjects covered include flow, physical modeling, sediment transport theory, techniques and instrumentation, morphodynamics and ecological topics, with special attention given to aspects of disasters relevant to sediment supply and integrated river management. This up-to-date compendium is essential reading for geomorphologists, river engineers and ecologists, river managers, fluvial sedimentologists and advanced students in these fields.

Autorentext

Daizo Tsutsumi, Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan

Jonathan B. Laronne, Department of Geography and Environmental Development, Ben Gurion University of the Negev, Beer Sheva, Israel

Inhalt
List of Contributors xix

Preface xxv

1 Computational Models of Flow, Sediment Transport and Morphodynamics in Rivers 1
Cristian Escauriaza, Chris Paola, and Vaughan R. Voller

1.1 Introduction 1

1.2 Numerical Simulations in Rivers 2

1.3 Choosing the Right Modeling Approach 13

1.4 Next Steps in Modeling 20

1.5 Concluding Questions 23

Acknowledgments 24

References 24

Discussion 29

2 Boulder Effects on Turbulence and Bedload Transport 33
A.N. (Thanos) Papanicolaou and Achilleas G. Tsakiris

2.1 Boulders in the Riverine Continuum 33

2.2 Scope and Objectives of the Study 36

2.3 Dataset Selection and Methodology 39

2.4 Mean Flow Field Around a Single, Wall-Mounted Boulder 47

2.5 Mean Vortex Structure Around a Wall-Mounted Boulder 51

2.6 Collective Effects of the Boulder Array 53

2.7 Sediment Transport Within a Boulder Array 56

2.8 Morphology of Depositional Patches Around Boulders 60

2.9 Concluding Remarks 61

Notation and Abbreviations 63

Acknowledgments 65

References 65

Discussion 71

3 Granular Flows Applied to Gravel-Bed Rivers: Particle-Scale Studies of the Mobilization of a Gravel Bed by the Addition of Fines 73
Kimberly M. Hill and Danielle Tan

3.1 Introduction 73

3.2 Insights from Rheological Models of Dry Dense Granular Flows 76

3.3 Discrete Element Model Simulations of Bimodal Mixtures in Bedload Transport 81

3.4 Conclusions 88

Notation and Abbreviations 89

Acknowledgments 92

References 92

Discussion 94

4 Particle Motions and Bedload Theory: The Entrainment Forms of the Flux and the Exner Equation 97
David Jon Furbish, Siobhan L. Fathel, and Mark W. Schmeeckle

4.1 Introduction 97

4.2 Sediment Ensembles and Rarefied Conditions 99

4.3 Entrainment Forms of the Flux and the Exner Equation 101

4.4 Distributions of Hop Distances and Travel Times 106

4.5 The Meaning of Continuous Functions Applied to Conditions of Rarefied Transport 111

4.6 Conclusions 113

Notation 114

Acknowledgments 115

References 115

Discussion 118

5 Revisiting the Morphological Approach: Opportunities and Challenges with Repeat High-Resolution Topography 121
Damià Vericat, Joseph M. Wheaton, and James Brasington

5.1 Introduction 121

5.2 The Morphological Approach: a Primer 122

5.3 Applying a Morphological Approach with HRT 128

5.4 Discussion 145

5.5 Conclusions 149

Acknowledgements 150

References 150

Discussion 155

6 Geomorphic Controls on Tracer Particle Dispersion in Gravel-Bed Rivers 159
Marwan A. Hassan and D. Nathan Bradley

6.1 Introduction 159

6.2 Bedload Estimates Using Tracers 160

6.3 Scales of Particle Motion 162

6.4 Types of Tracer Experiments and a Review of Results 162

6.5 Practical Relations for Travel Distance 165

6.6 Virtual Velocity 167

6.7 Burial Depth and Vertical Mixing 169

6.8 Depth of the Active Layer 171

6.9 Morphology 172

6.10 Bed Texture 176

6.11 Closing Remarks 177

Acknowledgments 178

References 179

Discussion 184

7 Bedload Transport Measurements with Geophones, Hydrophones, and Underwater Microphones (Passive Acoustic Methods) 185
Dieter Rickenmann

7.1 Introduction 185

7.2 Particle Impact Systems 187

7.3 Underwater Microphones 195

7.4 Important Findings Related to System Calibration 196

7.5 Some Operational Aspects to be Considered For Different Systems 200 7.6 Conclusions...