Sediment Transport Appendix
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Geomorphic Classification of Rivers
9.36 Geomorphic Classification of Rivers JM Buffington, U.S. Forest Service, Boise, ID, USA DR Montgomery, University of Washington, Seattle, WA, USA Published by Elsevier Inc. 9.36.1 Introduction 730 9.36.2 Purpose of Classification 730 9.36.3 Types of Channel Classification 731 9.36.3.1 Stream Order 731 9.36.3.2 Process Domains 732 9.36.3.3 Channel Pattern 732 9.36.3.4 Channel–Floodplain Interactions 735 9.36.3.5 Bed Material and Mobility 737 9.36.3.6 Channel Units 739 9.36.3.7 Hierarchical Classifications 739 9.36.3.8 Statistical Classifications 745 9.36.4 Use and Compatibility of Channel Classifications 745 9.36.5 The Rise and Fall of Classifications: Why Are Some Channel Classifications More Used Than Others? 747 9.36.6 Future Needs and Directions 753 9.36.6.1 Standardization and Sample Size 753 9.36.6.2 Remote Sensing 754 9.36.7 Conclusion 755 Acknowledgements 756 References 756 Appendix 762 9.36.1 Introduction 9.36.2 Purpose of Classification Over the last several decades, environmental legislation and a A basic tenet in geomorphology is that ‘form implies process.’As growing awareness of historical human disturbance to rivers such, numerous geomorphic classifications have been de- worldwide (Schumm, 1977; Collins et al., 2003; Surian and veloped for landscapes (Davis, 1899), hillslopes (Varnes, 1958), Rinaldi, 2003; Nilsson et al., 2005; Chin, 2006; Walter and and rivers (Section 9.36.3). The form–process paradigm is a Merritts, 2008) have fostered unprecedented collaboration potentially powerful tool for conducting quantitative geo- among scientists, land managers, and stakeholders to better morphic investigations. -
Seasonal Flooding Affects Habitat and Landscape Dynamics of a Gravel
Seasonal flooding affects habitat and landscape dynamics of a gravel-bed river floodplain Katelyn P. Driscoll1,2,5 and F. Richard Hauer1,3,4,6 1Systems Ecology Graduate Program, University of Montana, Missoula, Montana 59812 USA 2Rocky Mountain Research Station, Albuquerque, New Mexico 87102 USA 3Flathead Lake Biological Station, University of Montana, Polson, Montana 59806 USA 4Montana Institute on Ecosystems, University of Montana, Missoula, Montana 59812 USA Abstract: Floodplains are comprised of aquatic and terrestrial habitats that are reshaped frequently by hydrologic processes that operate at multiple spatial and temporal scales. It is well established that hydrologic and geomorphic dynamics are the primary drivers of habitat change in river floodplains over extended time periods. However, the effect of fluctuating discharge on floodplain habitat structure during seasonal flooding is less well understood. We collected ultra-high resolution digital multispectral imagery of a gravel-bed river floodplain in western Montana on 6 dates during a typical seasonal flood pulse and used it to quantify changes in habitat abundance and diversity as- sociated with annual flooding. We observed significant changes in areal abundance of many habitat types, such as riffles, runs, shallow shorelines, and overbank flow. However, the relative abundance of some habitats, such as back- waters, springbrooks, pools, and ponds, changed very little. We also examined habitat transition patterns through- out the flood pulse. Few habitat transitions occurred in the main channel, which was dominated by riffle and run habitat. In contrast, in the near-channel, scoured habitats of the floodplain were dominated by cobble bars at low flows but transitioned to isolated flood channels at moderate discharge. -
Culvert Design Transportation & the Environment Conference December 3, 2014 Chris Freiburger – Fisheries Division - DNR Perched Piping
Culvert Design Transportation & the Environment Conference December 3, 2014 Chris Freiburger – Fisheries Division - DNR Perched Piping Blockage Sediment What are we after? •Natural and dynamic stream channel •Passage of all aquatic organisms •Low maintenance, flood-resilient road Sizing & Placement of Stream Culverts The Stream Will Tell You! •Match Culvert Width to Bankfull Stream Width •Extend Culvert Length through side slope toe •Set Culvert Slope same as Stream Slope •Bury Culvert 1/6th Bankfull Stream Width •Offset Multiple Culverts (floodplain ~ splits lower buried one) (higher one ~ 1 ft. higher) •Align Culvert with Stream (or dig with stream sinuosity) •Consider Headcuts and Cut-Offs Dr. Sandy Verry Chief Research Hydrologist Forest Service Mesboac Culvert Design – 0’ • Match 3’ Bankfull width 6’ • Extend Culvert to side slope toe • Set on Channel Slope Set Slope Failure to set culverts on the same slope th as the stream (and bury them 1/6 widthBKF) is the single reason that many culverts do not allow for fish passage! Slope can be measured as: Slope along the bank (wider variation, than thalweg) Slope of the water surface (big errors at low flow or in flooded channels, good at moderate to bankfull flows) Slope of the thalweg (this, by far, is the best one) Measure a longitudinal profile to allow the precise placement of culverts. Precision Setting is the key to a fully functional riffle culvert installation At each point riffle 1. Bankfull riffle 2. Water surface Setting the elevation 3. Thalweg of the culvert invert True North Backsight upstream & riffle Benchmark downstream assures success! riffle riffle Measure Bankfull elevation, water surface elevation, and major thalweg topographic breaks (riffle top, riffle bottom, pool bottom), at each station, on the longitudinal profile 1997 LITTLE POKEGAMA CREEK PLOT 7 LONGITUDINAL 1003 1002 1001 1000 FT - 999 998 Bankfull elevation 997 ELEVATION 996 Slope = 0.0191 Water Surface elevation 995 Thalweg elevation 994 993 0 50 100 150 200 250 300 350 400 THALWEG DISTANCE-FT 1. -
Stream Restoration, a Natural Channel Design
Stream Restoration Prep8AICI by the North Carolina Stream Restonltlon Institute and North Carolina Sea Grant INC STATE UNIVERSITY I North Carolina State University and North Carolina A&T State University commit themselves to positive action to secure equal opportunity regardless of race, color, creed, national origin, religion, sex, age or disability. In addition, the two Universities welcome all persons without regard to sexual orientation. Contents Introduction to Fluvial Processes 1 Stream Assessment and Survey Procedures 2 Rosgen Stream-Classification Systems/ Channel Assessment and Validation Procedures 3 Bankfull Verification and Gage Station Analyses 4 Priority Options for Restoring Incised Streams 5 Reference Reach Survey 6 Design Procedures 7 Structures 8 Vegetation Stabilization and Riparian-Buffer Re-establishment 9 Erosion and Sediment-Control Plan 10 Flood Studies 11 Restoration Evaluation and Monitoring 12 References and Resources 13 Appendices Preface Streams and rivers serve many purposes, including water supply, The authors would like to thank the following people for reviewing wildlife habitat, energy generation, transportation and recreation. the document: A stream is a dynamic, complex system that includes not only Micky Clemmons the active channel but also the floodplain and the vegetation Rockie English, Ph.D. along its edges. A natural stream system remains stable while Chris Estes transporting a wide range of flows and sediment produced in its Angela Jessup, P.E. watershed, maintaining a state of "dynamic equilibrium." When Joseph Mickey changes to the channel, floodplain, vegetation, flow or sediment David Penrose supply significantly affect this equilibrium, the stream may Todd St. John become unstable and start adjusting toward a new equilibrium state. -
Logistic Analysis of Channel Pattern Thresholds: Meandering, Braiding, and Incising
Geomorphology 38Ž. 2001 281–300 www.elsevier.nlrlocatergeomorph Logistic analysis of channel pattern thresholds: meandering, braiding, and incising Brian P. Bledsoe), Chester C. Watson 1 Department of CiÕil Engineering, Colorado State UniÕersity, Fort Collins, CO 80523, USA Received 22 April 2000; received in revised form 10 October 2000; accepted 8 November 2000 Abstract A large and geographically diverse data set consisting of meandering, braiding, incising, and post-incision equilibrium streams was used in conjunction with logistic regression analysis to develop a probabilistic approach to predicting thresholds of channel pattern and instability. An energy-based index was developed for estimating the risk of channel instability associated with specific stream power relative to sedimentary characteristics. The strong significance of the 74 statistical models examined suggests that logistic regression analysis is an appropriate and effective technique for associating basic hydraulic data with various channel forms. The probabilistic diagrams resulting from these analyses depict a more realistic assessment of the uncertainty associated with previously identified thresholds of channel form and instability and provide a means of gauging channel sensitivity to changes in controlling variables. q 2001 Elsevier Science B.V. All rights reserved. Keywords: Channel stability; Braiding; Incision; Stream power; Logistic regression 1. Introduction loads, loss of riparian habitat because of stream bank erosion, and changes in the predictability and vari- Excess stream power may result in a transition ability of flow and sediment transport characteristics from a meandering channel to a braiding or incising relative to aquatic life cyclesŽ. Waters, 1995 . In channel that is characteristically unstableŽ Schumm, addition, braiding and incising channels frequently 1977; Werritty, 1997. -
5.1 Coarse Bed Load Sampling
University of Montana ScholarWorks at University of Montana Graduate Student Theses, Dissertations, & Professional Papers Graduate School 1997 The initiation of coarse bed load transport in gravel bed streams Andrew C. Whitaker The University of Montana Follow this and additional works at: https://scholarworks.umt.edu/etd Let us know how access to this document benefits ou.y Recommended Citation Whitaker, Andrew C., "The initiation of coarse bed load transport in gravel bed streams" (1997). Graduate Student Theses, Dissertations, & Professional Papers. 10498. https://scholarworks.umt.edu/etd/10498 This Dissertation is brought to you for free and open access by the Graduate School at ScholarWorks at University of Montana. It has been accepted for inclusion in Graduate Student Theses, Dissertations, & Professional Papers by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter free, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. -
Objective Identification of Pools and Riffles in a Human-Modified Stream System
Middle States Geographer, 2002, 35:52-60 OBJECTIVE IDENTIFICATION OF POOLS AND RIFFLES IN A HUMAN-MODIFIED STREAM SYSTEM Kelly M. Frothingham and Natalie Brown Department of Geography & Planning, Buffalo State College 1300 Elmwood Avenue Buffalo, NY 14222 ABSTRACT: Pools have been defined as topographic lows along a longitudinal stream profile and riffles are topographic highs. Past research has shown pools and riffles are the fundamental bedforms in meandering streams and that channel cross sections in meandering channels exhibit varying degrees of asymmetry that coincide with these bed form features. Two indices that identify pool and riffle bed forms are the bed differencing technique (bdt) developed by O'Neill and Abrahams (1984) and the areal difference asymmetry index (A') (Knighton. 1981). The purpose of this research was to use these indices to objectively identify pools and riffles in three reaches of a human-modified stream. Geomorphological data were collected in two meandering reaches and one straight reach ofthe East Branch ofCazenovia Creek, NY. Between 16 and 19 cross sections were surveyed in each reach during summer low flow conditions. The bdt identified more bed forms in the meandering reaches versus the straight channelized reach (six and two bed forms, respectively). Results from the asymmetry' analysis indicated that more cross sections in the two meandering reaches were asymmetrical (71 and 73% ofthe cross sections) versus 47% of the cross sections being asymmetrical in the straight reach. Moreover, asymmetrical cross sections generally corresponded with pool bed forms identified by the bdt and symmetrical cross sections corresponded with riffle bed forms identified hy the bdt. -
Re-Creating Meander Geometry Photo(S)
Practice Title Re-creating meander geometry Photo(s) Greene County streams after their meander geometry was restored to the extent necessary to move sediment and flow without excess erosion or deposition (bottom photos). The proper meander geometry is determined through detailed stream assessment. Also, a diagram showing the typical position of pools and riffles within a meandering stream, and a few other stream meander geometry patterns (top). Summary of Practice The winding pattern of a river or stream is called its meander pattern. These meanders result in a longer channel with a lower slope. These curves slow down the water and absorb energy, which helps to reduce the potential for erosion. The velocity of a stream is typically greatest on the outside of a meander bend. The increased force of this water often results in erosion along this bank, extending a short distance downstream. On the inside of the bend, the stream velocity typically decreases, which often results in the deposition of sediment, usually sand and gravel. If you could look at the long-term history of a valley over hundreds or thousands of years, you would see that the stream has moved back and forth across the valley bottom. In fact, this lateral migration of the channel, accompanied by down cutting, is what has formed the valley. Success in stream management is based on working with the stream, not against it. If a reach of channel is suffering unusual bank erosion, down cutting of the bed, aggradation, change of channel pattern, or other evidence of instability, a realistic approach to addressing these problems should be based on restoring the system’s equilibrium. -
Water Life: Riffles and Pools Stream Ecosystems Provide a Habitat Or
Water Life: Riffles and Pools Stream ecosystems provide a habitat or natural environment for many diverse aquatic organisms and plants. A deeper look indicates each stream has a distinctive anatomy as each is composed of a series of pools, riffles and runs. Pools: An area of the stream characterized by deep depths and slow current. Pools are typically created by the vertical force of water falling down over logs or boulders. The movement of the water carves a deeper indentation in the stream bed. Pools are important because they can provide depth and still water. Riffles: An area of stream characterized by shallow depths with fast, turbulent water. The riffles are short segments of the stream where water flow is agitated by rocks. The rocky Adapted from: bottom provides protection from predators, food http://share3.esd105.wednet.edu/rsandelin/ees/Resources/Flowing%20water%20concepts.htm deposition and shelter. Riffle depths vary depending upon stream size, but can be as shallow as 1 inch or deep as 1 meter. The turbulence and stream flow results in high dissolved oxygen concentration. Run: An area of stream characterized by moderate current, continuous surface and depths greater than riffles. Runs are stretches of the stream downstream of pools and riffles where stream flow and current are moderate. The smooth surface allows for light to penetrate. Microhabitats: Habitats are the natural environment in which an organism lives. The distinguishing abiotic conditions of riffles, pools and runs result in specialized environments that are known as microhabitats. The abiotic conditions (dissolved oxygen, turbidity, light and temperature) of these microhabitats can influence which aquatic species can survive and reproduce at that given location and time. -
The Form of a Channel
23 GEOMORPHOLOGY 201 READER The bankfull discharge is that flow at which the channel is completely filled. Wide variations are seen in the frequency with which the bankfull discharge occurs, although it generally has a return period of one to two years for many stable alluvial rivers. The geomorphological work carried out by a given flow depends not only on its size but also on its frequency of occurrence over a given period of time. The flow in river channels exerts hydraulic forces on the boundary (bed and banks). An important balance exists between the erosive force of the flow (driving force) and the resistance of the boundary to erosion (resisting force). This determines the ability of a river to adjust and modify the morphology of its channel. One of the main factors influencing the erosive power of a given flow is its discharge: the volume of flow passing through a given cross-section in a given time. Discharge varies both spatially and temporally in natural river channels, changing in a downstream direction and fluctuating over time in response to inputs of precipitation. Characteristics of the flow regime of a river include seasonal variations in discharge, the size and frequency of floods and frequency and duration of droughts. The characteristics of the flow regime are determined not only by the climate but also by the physical and land use characteristics of the drainage basin. Valley setting Channel processes are driven by flow and sediment supply, although the range of channel adjustments that are possible are often restricted by the valley setting. -
Three Dimensional Mobile Bed Dynamics for Sediment Transport Modeling
THREE DIMENSIONAL MOBILE BED DYNAMICS FOR SEDIMENT TRANSPORT MODELING DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Sean O’Neil, B.S., M.S. ***** The Ohio State University 2002 Dissertation Committee: Approved by Professor Keith W. Bedford, Adviser Professor Carolyn J. Merry Adviser Professor Diane L. Foster Civil Engineering Graduate Program c Copyright by Sean O’Neil 2002 ABSTRACT The transport and fate of suspended sediments continues to be critical to the understand- ing of environmental water quality issues within surface waters. Many contaminants of environmental concern within marine and freshwater systems are hydrophobic, thus read- ily adsorbed to bed material or suspended particles. Additionally, management strategies for evaluating and remediating the effects of dredging operations or marine construction, as well as legacy pollution from military and industrial processes requires knowledge of sediment-water interactions. The dynamic properties within the bed, the bed-water column inter-exchange and the transport properties of the flowing water is a multi-scale nonlin- ear problem for which the mobile bed dynamics with consolidation (MBDC) model was formulated. A new continuum-based consolidation model for a saturated sediment bed has been developed and verified on a stand-alone basis. The model solves the one-dimensional, vertical, nonlinear Gibson equation describing finite-strain, primary consolidation for satu- rated fine sediments. The consolidation problem is a moving boundary value problem, and has been coupled with a mobile bed model that solves for bed level variations and grain size fraction(s) in time within a thin layer at the bed surface. -
Modeling Forced Pool–Riffle Hydraulics in a Boulder-Bed Stream, Southern California ⁎ Lee R
Geomorphology 83 (2007) 232–248 www.elsevier.com/locate/geomorph Modeling forced pool–riffle hydraulics in a boulder-bed stream, southern California ⁎ Lee R. Harrison , Edward A. Keller Department of Earth Science, University of California, Santa Barbara, Santa Barbara, CA 93106, USA Received 2 May 2005; received in revised form 13 February 2006; accepted 13 February 2006 Available online 11 July 2006 Abstract The mechanisms which control the formation and maintenance of pool–riffles are fundamental aspects of channel form and process. Most of the previous investigations on pool–riffle sequences have focused on alluvial rivers, and relatively few exist on the maintenance of these bedforms in boulder-bed channels. Here, we use a high-resolution two-dimensional flow model to investigate the interactions among large roughness elements, channel hydraulics, and the maintenance of a forced pool–riffle sequence in a boulder-bed stream. Model output indicates that at low discharge, a peak zone of shear stress and velocity occurs over the riffle. At or near bankfull discharge, the peak in velocity and shear stress is found at the pool head because of strong flow convergence created by large roughness elements. The strength of flow convergence is enhanced during model simulations of bankfull flow, resulting in a narrow, high velocity core that is translated through the pool head and pool center. The jet is strengthened by a backwater effect upstream of the constriction and the development of an eddy zone on the lee side of the boulder. The extent of flow convergence and divergence is quantified by identifying the effective width, defined here as the width which conveys 90% of the highest modeled velocities.