Gravel-Bed Rivers
Process and Disasters

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.

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 200

Acknowledgement 201

References 201

Discussions 205

8 Calibration of Acoustic Doppler Current Profiler Apparent Bedload Velocity to Bedload Transport Rate 209
Colin D. Rennie, Damià Vericat, Richard D. Williams, James Brasington, and Murray Hicks

8.1 Introduction 209

8.2 aDcp Apparent Bedload Velocity 210

8.3 Previous Calibration Efforts 215

8.4 Rees River Survey: New Fractional Calibration Data 220

8.5 Discussion 223

8.6 Conclusions 226

Notation 226

Acknowledgements 227

References 228

Discussion 231

9 Modeling Surface–Subsurface Exchange of Heat and Nutrients 235
Daniele Tonina, Alessandra Marzadri, and Alberto Bellin

9.1 Introduction 235

9.2 Hyporheic Hydraulics 238

9.3 Hyporheic Residence Time 241

9.4 Damköhler Numbers 244

9.5 Role of Stream Morphology on Nitrous Oxide Emissions 247

9.6 Conclusions and Research Needs 249

Notation 250

Acknowledgments 251

Appendix 252

References 253

Discussion 259

10 Ecological Effects of Flow Intermittence in Gravel-Bed Rivers 261
Thibault Datry

10.1 Introduction 261

10.2 Flow Intermittence in GBRs from a Hydrological Perspective 261

10.3 Flow Intermittence in GBRs: an Ecohydrological Perspective 270

10.4 Intermittent GBRs as Coupled Aquatic–Terrestrial Disturbed Ecosystems 284

10.5 Flow Intermittence in GBRs: Research Needs and Open Questions 286

11 Catastrophic Deposition of Gravel from Outbreak Floods 299
Paul A. Carling

11.1 Introduction 299

11.2 Depositional Context 300

11.3 A Framework for Description of Megaflood Sedimentary Successions 301

11.4 Typical Sequences Within a Succession 302

11.5 Discussion 315

11.6 Conclusions 318

Acknowledgements 318

References 319

Discussion 325

12 Linkage Between Sediment Transport and Supply in Mountain Rivers 329
Mikaël Attal

12.1 Introduction 329

12.2 Sediment Supply to Mountain Rivers and its Influence on the Characteristics of the Sediment Available for Fluvial Transport 330

12.3 Influence of Varying Sediment Availability on Sediment Transport and Export During Floods 336

12.4 Concluding Remarks 345

Acknowledgement 345

References 345

Discussion 351

13 Geomorphic Responses to Dam Removal in the United States – a Two-Decade Perspective 355
Jon J. Major, Amy E. East, Jim E. O’Connor, Gordon E. Grant, Andrew C. Wilcox, Christopher S. Magirl, Mathias J. Collins, and Desiree D. Tullos

13.1 Introduction 355

13.2 Reservoir and Downstream Channel Responses to Dam Removal 357

13.3 Factors Influencing Responses to Dam Removals 366

13.4 Time Scales of Channel Responses to Dam Removals 373

13.5 Common Findings from Analyses of Responses to Dam Removals 375

Acknowledgments 377

References 377

Discussion 381

14 Reservoir Sediment Flushing and Replenishment Below Dams: Insights from Japanese Case Studies 385
Tetsuya Sumi, Sameh Kantoush, Taymaz Esmaeili, and Giyoung Ock

14.1 Introduction 385

14.2 Present State of Reservoir Sedimentation in Japan 386

14.3 Selecting Suitable Sediment Management Options 388

14.4 Sediment Flushing 390

14.5 Sediment Replenishment 405

14.6 Conclusions 410

Acknowledgment 410

References 411

15 Bedload Transport in Laboratory Rivers: The Erosion–Deposition Model 415
Eric Lajeunesse, Olivier Devauchelle, Florent Lachaussée, and Philippe Claudin

15.1 Introduction 415

15.2 The Erosion–Deposition Model 417

15.3 Deposition Length and Bedforms 425

15.4 Spreading of a Plume of Tracers 427

15.5 Conclusions 430

Notation 430

Acknowledgements 431

References 431

Discussion 435

16 Bedforms, Structures, Patches, and Sediment Supply in Gravel-Bed Rivers 439
Jeremy G. Venditti, Peter A. Nelson, Ryan W. Bradley, Dan Haught, and Alessandro B. Gitto

16.1 Introduction 439

16.2 Bedload Transport, Sediment Supply, and Bed Mobility 439

16.3 Bed Features in Gravel-Bed Rivers 446

16.4 A Phase Diagram for Bed Features in a Gravel-Bedded River 456

16.5 Perspective and Conclusions 458

Acknowledgments 460

References 460

Discussion 464

17 Linking Debris Flows and Landslides to Large Floods in Gravel-Bed Rivers 467
Lorenzo Marchi

17.1 Introduction 467

17.2 Interactions Between Mass Wasting and Floods in Gravel-Bed Rivers 468

17.3 Approaches to Prediction 477

17.4 Discussion 485

17.5 Conclusions 487

Acknowledgements 487

References 487

Discussion 493

18 Gravel Riverbed Processes Resulting from Large-Scale Landslides 497
Chjeng-Lun Shieh and Yu-Shiu Chen

18.1 Introduction 497

18.2 Case Study: Shoufeng River 498

18.3 Case Study: Taimaili River 508

18.4 Conclusion 512

Acknowledgements 513

References 513

Discussion 513

19 Gravel-Bed River Management Focusing on Finer Sediment Behaviour 517
Koichi Fujita

19.1 Introduction 517

19.2 Background Information 518

19.3 Vital Points to Advance Channel Management Strategy 522

19.4 Role of Finer Sediment in the Expansion of Dense Vegetation Areas in Segment-1G

Reaches 526

19.5 Floodplain Accretion by Finer Sediment Deposition and Resulting Channel Narrowing in Segment-2G Reaches 532

19.6 Engineering Framework for Gravel-Bed River Management 540

Notation 541

Acknowledgements 542

References 543

Discussion 544

20 Lahar Flow Disaster, Human Activities, and Risk Mitigation on Volcanic Rivers: Case Study of Rivers on Mount Merapi Slopes, Indonesia 549
Djoko Legono and Adam Pamudji Rahardjo

20.1 Introduction 549

20.2 Riverbed Characteristics 552

20.3 Human Activities 554

20.4 Sediment Management and Risk Mitigation 559

20.5 Conclusions 564

Acknowledgements 564

References 565

21 A Method for Estimating the Porosity of Sediment Mixtures and Application to a Bed-Porosity Variation Model 567
Masaharu Fujita, Muhammad Sulaiman, and DaizoTsutsumi

21.1 Introduction 567

21.2 Identification of Grain-Size Distribution 569

21.3 Relationship Between the Geometric Parameters of Grain-Size Distributions and Porosity 576

21.4 An Algorithm for Estimating the Porosity 581

21.5 Application to Bed-Porosity Variation Model 583

21.6 Conclusions 586

Acknowledgements 586

References 586

Discussion 588

22 Gravel Sorting and Variation of Riverbeds Containing Gravel, Sand, Silt, and Clay 591
Masato Sekine and Yuki Hiramatsu

22.1 Introduction 591

22.2 Summary of Experiments 592

22.3 Vertical Sorting and Variation of the Riverbed with Extremely Wide Range

of Sediment Sizes 597

22.4 Variation of a Clay Bed Caused by Sand or Gravel Transport Over It 601

22.5 Conclusions 606

Notation 607

Acknowledgement 608

References 608

23 Modeling Stratigraphy-Based Gravel-Bed River Morphodynamics 609
Enrica Viparelli, Astrid Blom, and Ricardo R. Hernandez Moreira

23.1 Introduction 609

23.2 Model Formulation 612

23.3 Application to a Case Inspired by the Trinity River, California, United States 621

23.4 Conclusions 630

Notation 631

Acknowledgments 633

References 633

Discussion 636

24 Sediment Processes in Bedrock–Alluvial Rivers: Research Since 2010 and Modelling the Impact of Fluctuating Sediment Supply on Sediment Cover 639
Rebecca A. Hodge

24.1 Introduction 639

24.2 Differences Between Sediment Processes in Alluvial and Bedrock–Alluvial Channels 639

24.3 Review of Sediment Processes in Bedrock–alluvial Rivers Since 2010 640

24.4 Literature Review Findings and Cross-Cutting Themes 646

24.5 Outstanding Research Questions 647

24.6 Implications for Modelling Sediment Processes in Bedrock–Alluvial Rivers 650

24.7 An Application of a Numerical Model of Sediment Processes 651

24.8 Conclusions 663

Acknowledgements 664

References 664

Discussion 668

25 Modelling Braided Channels Under Unsteady Flow and the Effect of Spatiotemporal Change of Vegetation on Bed and Channel Geometry 671
Hiroshi Takebayashi

25.1 Introduction 671

25.2 Numerical Analysis Method 674

25.3 Flume Experiments: Method and Hydraulic Conditions 685

25.4 Results and Discussion 685

25.5 Conclusions 694

Notation 696

Acknowledgements 698

References 699

Discussion 701

26 Modelling of Mixed-Sediment Morphodynamics in Gravel-Bed Rivers Using the Active-Layer Approach: Insights from Mathematical and Numerical Analysis 703
Annunziato Siviglia, Guglielmo Stecca, and Astrid Blom

26.1 Introduction 703

26.2 The Saint-Venant–Hirano Model 705

26.3 Mathematical Analysis 708

26.4 Assessment of Numerical Solutions 717

26.5 Conclusions and Research Perspectives 722

Acknowledgements 725

References 726

Discussion 728

27 Physical and Numerical Modelling of Large Wood and Vegetation in Rivers 729
Walter Bertoldi and Virginia Ruiz-Villanueva

27.1 Introduction 729

27.2 Physical Modelling of Vegetation 730

27.3 Numerical Modelling of Riparian Vegetation 735

27.4 Physical Modelling of Large Wood 739

27.5 Numerical Modelling of Instream Large Wood Transport 742

27.6 Future Challenges 747

Acknowledgements 748

References 748

28 Fluvial Gravels on Mars: Analysis and Implications 755
William E. Dietrich, Marisa C. Palucis, Rebecca M. E. Williams, Kevin W. Lewis, Frances Rivera-Hernandez, and Dawn Y. Sumner

28.1 Introduction 755

28.2 First Observations of Fluvial Conglomerates on Mars 756

28.3 Some Fluvial Conglomerates on the Way to Mount Sharp 758

28.4 Estimates of Stream Velocity, Channel Discharge, and Gravel Mobility on Mars 759

28.5 Runoff Volume and Implications for Climate 773

28.6 Conclusions 775

Acknowledgments 776

References 776

Discussion 779

Index 785

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