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ID SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 An e-book by Gary Parker St. Anthony Falls Laboratory, Mississippi River at 3rd Avenue SE Minneapolis MN 55414 USA St. Anthony Falls Laboratory is a part of the University of Minnesota Nile Delta, Egypt NASA Image from Internet Copper Creek Fan, Death Valley, USA Image courtesy Roger Hooke 1 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Notes on the Use of this e-book This e-book is a work in progress. • The basic lectures on morphodynamics are presented in PowerPoint files. • The lectures are illustrated with many Excel files, most of which illustrate the principles of morphodynamics in terms of code in Visual Basic for Applications (VBA). The code is embedded in Excel and is made freely available to the user. • Several Word files allow for extended explanation of the principles behind the code in the Excel files. • Video clips are used to illustrate various aspects of morphodynamics. The PowerPoint, Excel and Word files, as well as the video clips (mpegs) are gradually being uploaded to the following site: http://www.ce.umn.edu/~parker , where they are being made available for free. The video clips must be downloaded to the same directory containing the PowerPoint presentations if they are to run without relinking. In order to run the code in VBA, it is necessary to set the Macro security level to no higher than “medium” (from Excel, “Tools”, “Macro”, “Security…”; set to “medium”). 2 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Dedication This e-book is dedicated to Mohammed Akram Gill, an outstanding morphodynamicist who was forced to flee his university position in Africa due to racial intolerance. Although the United States offered him and his family refuge and a livelihood, it did not offer him a chance to continue employment at a university or research institution. Gill, M.A. 1988 Hyperbolic model for aggrading channels. Journal of Engineering Mechanics 114(7): 1246-1255. 3 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Introduction This e-book is about the morphodynamics of rivers and turbidity currents. In particular, it is concerned with the application of the principles of hydraulics and sediment transport to one-dimensional (1D) numerical modeling of the morphodynamic evolution of such features as a) river deltas, b) incising bedrock streams and c) evolution of submarine fans. This e-book represents an attempt to write a “different” kind of technical book. The basic material is presented in chapters written in PowerPoint. These chapters then quote Excel files, which contain working software written in Visual Basic for Applications. Some documentation for this software is provided in Word files. Finally, several video clips are incorporated into the e-book. This e-book has evolved from two courses that the author taught while on sabbatical leave in 2002. “1D and Quasi-2D Numerical Modeling of Sediment Morphodynamics,” was taught in the Department of Earth, Atmospheric and Planetary Science at the Massachusetts Institute of Technology. “Fundamentals of Sediment Transport and Morphodynamics with Applications To Sedimentation 4 On Fluvial Fans And Fan-deltas,” was taught at Tokyo Institute of Technology. 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Acknowledgements This e-book represents a contribution to the research efforts of the National Center for Earth-surface Dynamics, based at St. Anthony Falls Laboratory, University of Minnesota, http://www.nced.umn.edu. NCED participants Bill Dietrich, David Mohrig and Vaughan Voller contributed in various ways to the formulation and writing of the e-book. The following people contributed in a substantial way to this e-book. • Syunsuke Ikeda, with whom the author has exchanged numerous ideas concerning river morphodynamics, and who invited the author to the Tokyo Institute of Technology to teach the course “Fundamentals of Sediment Transport and Morphodynamics with Applications To Sedimentation On Fluvial Fans And Fan-deltas.” • Chris Paola, whose numerical modeling of the stratigraphy of subsiding basins helped motivate the author’s interest in fluvial fans and fan-deltas. • Waraporn Parker, my wife, who insisted that I should actually finish this book. • Kelin Whipple, who worked together with the author on fan morphodynamics, and who invited the author to the Massachusetts Institute of Technology under a Crosby Lectureship to teach the course “1D and Quasi-2D Numerical Modeling of Sediment Morphodynamics.” In addition, the following of my (mostly former) graduate students and postdoctoral fellows contributed to the work presented in this book: Yoshihisa Akamatsu, Alessandro Cantelli, Yantao Cui, Phairot Chatanantavet, Jasim Imran, Norihiro Izumi, Svetlana Kostic, J. 5 Wesley Lauer, Sun Tao, Horacio Toniolo, Miguel Wong. 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Table of Contents Part 1: 1D Sediment Transport 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Felix M. Exner and the Origins of River Morphodynamics Characterization of Sediment and Grain Size Distributions Bankfull Characteristics of Rivers Relations for the Conservation of Bed Sediment Review of 1D Open-Channel Hydraulics Threshold of Motion and Suspension Relations for 1D Bedload Transport Fluvial Bedforms Relations for Hydraulic Resistance in Rivers Relations for the Entrainment and 1D Transport of Suspended Sediment Sample Calculation for Bed Load, Suspended Load and Total Load Bulk Relations for Transport of Total Bed Material Load The Quasi-Steady Approximation 6 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Table of Contents Part 2: Morphodynamics of Rivers 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 1D Aggradation and Degradation of Rivers: Normal Flow Assumption Extension of 1D Model to Include Bank Erosion and Floodplain Deposition Morphodynamics of Bedrock-Alluvial Transitions Aggradation and Degradation of Rivers Transporting Gravel Mixtures Mobile and Static Armor in Gravel-bed Streams Effect of the Hydrograph on Morphology of Gravel-bed Streams Aggradation and Degradation of Rivers: Backwater Formulation Response of a Sand-bed River to a Dredge Slot Morphodynamics of Recirculating and Sediment-Feed Flumes Transportational Cyclic Steps Approximate Formulation for Slope and Bankfull Geometry of Rivers Long Profiles of Rivers, with an Application on the Effect of Base Level Rise on Long Profiles 26. Rivers Flowing into Subsiding Basins: Upward Concavity of Long Profiles and Downstream Fining 7 27. Morphodynamics of Gravel-Sand Transitions 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Table of Contents Part 2: Morphodynamics of Rivers (contd.) 28. 29. 30. 31. Tracers in Gravel-bed Streams Knickpoint Migration in Bedrock Streams Bedrock Incision due to Wear (Abrasion) Erosional Narrowing and Widening of a Channel After Dam Removal 8 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Table of Contents Part 3: Fluvial Fans and Fan-deltas 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. Introduction to Fluvial Fans and Fan-deltas Modeling of Fluvial Fans and Bajadas in Subsiding Basins Morphodynamics of Rivers Ending In 1D Deltas Rivers Ending in 1D Deltas Carrying Sediment Size Mixtures Modeling of Rivers On 2D in Fan-deltas: Fixed-width Channel(s) Modeling of Rivers On 2D in Fan-deltas: Self-formed Channel(s) Response of Rivers with Deltas to Rising Base Level: The Muto Delta Response of Rivers with Deltas to Rising Base Level: Field Application Effect of Main-Stem Base Level Rise on a Tributary Cellular Modeling of 2D Fan-deltas with Self-formed Channel(s) 9 1D SEDIMENT TRANSPORT MORPHODYNAMICS with applications to RIVERS AND TURBIDITY CURRENTS © Gary Parker November, 2004 Table of Contents Part 4: Morphodynamics of Subaqueous Fans and Fan-deltas Deposited by Turbidity Currents, and Co-evolving Fluvial/Turbidity Current Fan-deltas 42. 43. 44. 45. 46. Introduction to Sublacustrine and Submarine Fans and Canyons Dynamics of 1D Turbidity Currents Plunging of Turbidity Currents Modeling of Purely Depositional 1D and 2D Subaqueous Fans Fluvial Deltas and Fan-deltas with Co-evolving Fluvial Topset, Avalanching Foreset and Bottomset Deposited from Turbidity Currents 47. Deposition in Diapiric Minibasins 48. Reservoir Sedimentation 49. Long Profile of Net-depositional Submarine Channels 50. Ignitive Turbidity Currents 51. Genesis of Submarine Canyons 52. Notes in Closing Appendix I: References Appendix II: Notation 10