Chapter 10 Movement of Sediment by Water Flows
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Measurement of Bedload Transport in Sand-Bed Rivers: a Look at Two Indirect Sampling Methods
Published online in 2010 as part of U.S. Geological Survey Scientific Investigations Report 2010-5091. Measurement of Bedload Transport in Sand-Bed Rivers: A Look at Two Indirect Sampling Methods Robert R. Holmes, Jr. U.S. Geological Survey, Rolla, Missouri, United States. Abstract Sand-bed rivers present unique challenges to accurate measurement of the bedload transport rate using the traditional direct sampling methods of direct traps (for example the Helley-Smith bedload sampler). The two major issues are: 1) over sampling of sand transport caused by “mining” of sand due to the flow disturbance induced by the presence of the sampler and 2) clogging of the mesh bag with sand particles reducing the hydraulic efficiency of the sampler. Indirect measurement methods hold promise in that unlike direct methods, no transport-altering flow disturbance near the bed occurs. The bedform velocimetry method utilizes a measure of the bedform geometry and the speed of bedform translation to estimate the bedload transport through mass balance. The bedform velocimetry method is readily applied for the estimation of bedload transport in large sand-bed rivers so long as prominent bedforms are present and the streamflow discharge is steady for long enough to provide sufficient bedform translation between the successive bathymetric data sets. Bedform velocimetry in small sand- bed rivers is often problematic due to rapid variation within the hydrograph. The bottom-track bias feature of the acoustic Doppler current profiler (ADCP) has been utilized to accurately estimate the virtual velocities of sand-bed rivers. Coupling measurement of the virtual velocity with an accurate determination of the active depth of the streambed sediment movement is another method to measure bedload transport, which will be termed the “virtual velocity” method. -
Sedimentation and Shoaling Work Unit
1 SEDIMENTARY PROCESSES lAND ENVIRONMENTS IIN THE COLUMBIA RIVER ESTUARY l_~~~~~~~~~~~~~~~7 I .a-.. .(.;,, . I _e .- :.;. .. =*I Final Report on the Sedimentation and Shoaling Work Unit of the Columbia River Estuary Data Development Program SEDIMENTARY PROCESSES AND ENVIRONMENTS IN THE COLUMBIA RIVER ESTUARY Contractor: School of Oceanography University of Washington Seattle, Washington 98195 Principal Investigator: Dr. Joe S. Creager School of Oceanography, WB-10 University of Washington Seattle, Washington 98195 (206) 543-5099 June 1984 I I I I Authors Christopher R. Sherwood I Joe S. Creager Edward H. Roy I Guy Gelfenbaum I Thomas Dempsey I I I I I I I - I I I I I I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFACE The Columbia River Estuary Data Development Program This document is one of a set of publications and other materials produced by the Columbia River Estuary Data Development Program (CREDDP). CREDDP has two purposes: to increase understanding of the ecology of the Columbia River Estuary and to provide information useful in making land and water use decisions. The program was initiated by local governments and citizens who saw a need for a better information base for use in managing natural resources and in planning for development. In response to these concerns, the Governors of the states of Oregon and Washington requested in 1974 that the Pacific Northwest River Basins Commission (PNRBC) undertake an interdisciplinary ecological study of the estuary. At approximately the same time, local governments and port districts formed the Columbia River Estuary Study Taskforce (CREST) to develop a regional management plan for the estuary. PNRBC produced a Plan of Study for a six-year, $6.2 million program which was authorized by the U.S. -
Drainage-Design-Manual.Pdf
City of El Paso Engineering Department Drainage Design Manual May 2Ol3 City of El Paso-Engineering Department Drainage Design Manual 19. Green Infrostruclure - OPTIONAL 19. Green Infrastructure - OPTIONAL 19.1. Background and Purpose Development and urbanization alter and inhibit the natural hydrologic processes of surface water infiltration, percolation to groundwater, and evapotranspiration. Prior to development, known as predevelopment conditions, up to half of the annual rainfall infiltrates into the native soils. In contrast, after development, known as post-development conditions, developed areas can generate up to four times the amount ofannual runoff and one-third the infiltration rate of natural areas. This change in conditions leads to increased erosion, reduced groundwater recharge, degraded water quality, and diminished stream flow. Traditional engineering approaches to stormwater management typically use concrete detention ponds and channels to convey runoff rapidly from developed surfaces into drainage systems, discharging large volumes of stormwater and pollutants to downstream surface waters, consume land and prevent infiltration. As a result, stormwater runoff from developed land is a significant source of many water quality, stream morphology, and ecological impairments. Reducing the overall imperviousness and using the natural drainage features of a site are important design strategies to maintain or enhance the baseline hydrologic functions of a site after development. This can be achieved by applying sustainable stormwater management (SSWM) practices, which replicate natural hydrologic processes and reduce the disruptive effects of urban development and runoff. SSWM has emerged as an altemative stormwater management approach that is complementary to conventional stormwater management measures. It is based on many ofthe natural processes found in the environment to treat stormwater runoff, balancing the need for engineered systems in urban development with natural features and treatment processes. -
Particle Size Distribution Controls the Threshold Between Net Sediment
PUBLICATIONS Geophysical Research Letters RESEARCH LETTER Particle Size Distribution Controls the Threshold Between 10.1002/2017GL076489 Net Sediment Erosion and Deposition in Suspended Key Points: Load Dominated Flows • New flow power sediment entrainment model scales with flow R. M. Dorrell1 , L. A. Amy2, J. Peakall3, and W. D. McCaffrey3 depth instead of particle size and incorporates capacity and 1Energy and Environment Institute, University of Hull, Hull, UK, 2School of Earth Sciences, University College Dublin, Dublin, competence limits 3 • Suspended load, at the threshold Ireland, School of Earth and Environment, University of Leeds, Leeds, UK between net erosion and deposition, is shown to be controlled by the particle size distribution Abstract The central problem of describing most environmental and industrial flows is predicting when • Flow power model offers an order of material is entrained into, or deposited from, suspension. The threshold between erosional and magnitude, or better, improvement in fl predicting the erosional-depositional depositional ow has previously been modeled in terms of the volumetric amount of material transported in threshold suspension. Here a new model of the threshold is proposed, which incorporates (i) volumetric and particle size limits on a flow’s ability to transport material in suspension, (ii) particle size distribution effects, and (iii) a fi Supporting Information: new particle entrainment function, where erosion is de ned in terms of the power used to lift mass from the • Table S1 bed. While current suspended load transport models commonly use a single characteristic particle size, • Supporting Information SI the model developed herein demonstrates that particle size distribution is a critical control on the threshold between erosional and depositional flow. -
Bed-Load Transport Equation for Sheet Flow
TECHNICAL NOTES Bed-Load Transport Equation for Sheet Flow Athol D. Abrahams1 Abstract: When open-channel flows become sufficiently powerful, the mode of bed-load transport changes from saltation to sheet flow. Where there is no suspended sediment, sheet flow consists of a layer of colliding grains whose basal concentration approaches that of the stationary bed. These collisions give rise to a dispersive stress that acts normal to the bed and supports the bed load. An equation for predicting the rate of bed-load transport in sheet flow is developed from an analysis of 55 flume and closed conduit experiments. The ϭ ϭ ϭ ϭ ϭ ␣ϭ equation is ib where ib immersed bed-load transport rate; and flow power. That ib implies that eb tan ub /u, where eb ϭ ϭ ␣ϭ Bagnold’s bed-load transport efficiency; ub mean grain velocity in the sheet-flow layer; and tan dynamic internal friction coeffi- ␣Ϸ Ϸ Ϸ cient. Given that tan 0.6 for natural sand, ub 0.6u, and eb 0.6. This finding is confirmed by an independent analysis of the experimental data. The value of 0.60 for eb is much larger than the value of 0.12 calculated by Bagnold, indicating that sheet flow is a much more efficient mode of bed-load transport than previously thought. DOI: 10.1061/͑ASCE͒0733-9429͑2003͒129:2͑159͒ CE Database keywords: Sediment transport; Bed loads; Geomorphology. Introduction transport process. In contrast, the bed-load transport equation pro- When open-channel flows transporting noncohesive sediments posed here is extremely simple and entirely empirical. -
Delft Hydraulics
Prepared for: DG Rijkswaterstaat, Rijksinstituut voor Kust en Zee | RIKZ Description of TRANSPOR2004 and Implementation in Delft3D-ONLINE FINAL REPORT Report November 2004 Z3748.00 WL | delft hydraulics Prepared for: DG Rijkswaterstaat, Rijksinstituut voor Kust en Zee | RIKZ Description of TRANSPOR2004 and Implementation in Delft3D-ONLINE FINAL REPORT L.C. van Rijn, D.J.R. Walstra and M. van Ormondt Report Z3748.10 WL | delft hydraulics CLIENT: DG Rijkswaterstaat Rijks-Instituut voor Kust en Zee | RIKZ TITLE: Description of TRANSPOR2004 and Implementation in Delft3D-ONLINE, FINAL REPORT ABSTRACT: In 2003 much effort has been spent in the improvement of the DELFT3D-ONLINE model based on the engineering sand transport formulations of the TRANSPOR2000 model (TR2000). This work has been described in Delft Hydraulics Report Z3624 by Van Rijn and Walstra (2003). However, the engineering sand transport model TR2000 has recently been updated into the TR2004 model within the EU-SANDPIT project. The most important improvements involve the refinement of the predictors for the bed roughness and the suspended sediment size. Up to now these parameters had to be specified by the user of the models. As a consequence of the use of predictors for bed roughness and suspended sediment size, it was necessary to recalibrate the reference concentration of the suspended sediment concentration profile. The formulations (including the newly derived formulations of TR2004) implemented in this 3D-model are described in detail. The implementation of TR2004 in Delft3D-ONLINE is part of an update of Delft3D which involves among others: the extension of the model to be run in profile mode, the synchronisation of the roughness formulations and inclusion of two breaker delay concepts. -
Formulae of Sediment Transport in Unsteady Flows (Part 2) Shu-Qing Yang
Chapter Formulae of Sediment Transport in Unsteady Flows (Part 2) Shu-Qing Yang Abstract Sediment transport (ST) in unsteady flows is a complex phenomenon that the existing formulae are often invalid to predict. Almost all existing ST formulae assume that sediment transport can be fully determined by parameters in streamwise direc- tion without parameters in vertical direction. Different from this assumption, this paper highlights the importance of vertical motion and the vertical velocity is suggested to represent the vertical motion. A connection between unsteadiness and vertical velocity is established. New formulae in unsteady flows have been developed from inception of sediment motion, sediment discharge to suspension’s Rouse num- ber. It is found that upward vertical velocity plays an important role for sediment transport, its temporal and spatial alternations are responsible for the phase lag phenomenon and bedform formation. Reasonable agreement between the measured and the proposed conceptual model was achieved. Keywords: unsteady flow, shields number, rouse number, sediment transport, vertical velocity 1. Introdution Sediment transport is the movement of solid particles driven by fluid like water or wind in rivers, lakes, reservoirs, coastal waters. Generally, in the real world the flow is unsteady like flood waves, tidal waves and wind waves, because steady and uniform flows are very rare in reality. Even so, it is understandable that sediment transport is first observed under well controlled conditions in laboratory, and then the data are collected to calibrate the models. These formulae are further examined using field data by assuming the laboratory flow conditions (generally steady and uniform flows) can be extended to rivers and coastal waters (generally unsteady and non-uniform). -
Chapter 14. Streams and Floods
Physical Geology, First University of Saskatchewan Edition is used under a CC BY-NC-SA 4.0 International License Read this book online at http://openpress.usask.ca/physicalgeology/ Chapter 14. Streams and Floods Adapted by Joyce M. McBeth, University of Saskatchewan from Physical Geology by Steven Earle Learning Objectives After carefully reading this chapter, completing the exercises within it, and answering the questions at the end, you should be able to: • Explain the hydrological cycle, its relevance to streams, and describe the residence time of water in these systems • Describe what a drainage basin is, and explain the origins of the different types of drainage patterns • Explain how streams become graded, and how certain geological and anthropogenic changes can result in a stream becoming ungraded • Describe the formation of stream terraces • Describe the processes that move sediments in streams, and how changes in stream velocity affect the types of sediments that are moved by the stream • Explain the origin of natural stream levees • Describe the process of stream evolution and the types of environments where one would expect to find straight-channel, braided, and meandering streams • Describe the annual flow characteristics of typical streams in Canada and the processes that lead to flooding • Describe some of the important historical floods in Canada • Determine the probability of floods of various magnitudes, based on the flood history of a stream • Explain some of the steps that we can take to limit damage from flooding Why Study Streams? Figure 14.1 A small waterfall on Johnston Creek in Johnston Canyon, Banff National Park, AB Source: Steven Earle (2015) CC BY 4.0 view source https://opentextbc.ca/geology/ Chapter 14. -
Classifying Rivers - Three Stages of River Development
Classifying Rivers - Three Stages of River Development River Characteristics - Sediment Transport - River Velocity - Terminology The illustrations below represent the 3 general classifications into which rivers are placed according to specific characteristics. These categories are: Youthful, Mature and Old Age. A Rejuvenated River, one with a gradient that is raised by the earth's movement, can be an old age river that returns to a Youthful State, and which repeats the cycle of stages once again. A brief overview of each stage of river development begins after the images. A list of pertinent vocabulary appears at the bottom of this document. You may wish to consult it so that you will be aware of terminology used in the descriptive text that follows. Characteristics found in the 3 Stages of River Development: L. Immoor 2006 Geoteach.com 1 Youthful River: Perhaps the most dynamic of all rivers is a Youthful River. Rafters seeking an exciting ride will surely gravitate towards a young river for their recreational thrills. Characteristically youthful rivers are found at higher elevations, in mountainous areas, where the slope of the land is steeper. Water that flows over such a landscape will flow very fast. Youthful rivers can be a tributary of a larger and older river, hundreds of miles away and, in fact, they may be close to the headwaters (the beginning) of that larger river. Upon observation of a Youthful River, here is what one might see: 1. The river flowing down a steep gradient (slope). 2. The channel is deeper than it is wide and V-shaped due to downcutting rather than lateral (side-to-side) erosion. -
River Processes- Erosion, Transportation and Deposition Task 1: for Each of the Processes of Erosion and Transportation Draw a Diagram Show the Process at Work
River Processes- Erosion, Transportation and Deposition Task 1: For each of the processes of erosion and transportation draw a diagram show the process at work In the upper course of the main process is Erosion. This is where the bed and banks of the river are worn away. A river can erode in one of four ways: Process Definition Diagram Hydraulic the sheer force of water hitting the action banks of the river: Abrasion fine material rubs against the riverbank The bank is worn away by a sand- papering action called abrasion, and collapses. This occurs on the outside of meanders. Attrition material is moved along the bed of a river, collides with other material, and breaks up into smaller pieces. Corrosion rocks forming the banks and bed of a river are dissolved by acids in the water. Once the material is eroded it can then be transported by one of four ways, which will depend upon the energy of the river: Process Definition Diagram Traction large rocks and boulders are rolled along the bed of the river. Saltation smaller stones are bounced along the bed of the river Suspension fine material which is carried by the water and which gives the river its 'muddy' colour. Solution dissolved material transported by the river. In the middle and lower course, the land is much flatter, this means that the river is flowing more slowly and has much less energy. The river starts to deposit (drop) the material that it has been carry Deposition Challenge: Add labels onto the diagram to show where all of the processes could be happening in the river channel. -
Sediment Bed-Load Transport: a Standardized Notation
geosciences Article Sediment Bed-Load Transport: A Standardized Notation Ulrich Zanke 1,2,* and Aron Roland 3 1 TU, Darmstadt, Inst. für Wasserbau und Hydraulik, 64287 Darmstadt, Germany 2 Z & P—Prof. Zanke & Partner, Ackerstr. 21, D-30826 Garbsen-Hannover, Germany 3 CEO BGS-ITE, Pfungstaedter Straße 20, D-64297 Darmstadt, Germany; [email protected] * Correspondence: [email protected] Received: 7 August 2020; Accepted: 1 September 2020; Published: 16 September 2020 Abstract: Morphodynamic processes on Earth are a result of sediment displacements by the flow of water or the action of wind. An essential part of sediment transport takes place with permanent or intermittent contact with the bed. In the past, numerous approaches for bed-load transport rates have been developed, based on various fundamental ideas. For the user, the question arises which transport function to choose and why just that one. Different transport approaches can be compared based on measured transport rates. However, this method has the disadvantage that any measured data contains inaccuracies that correlate in different ways with the transport functions under comparison. Unequal conditions also exist if the factors of transport functions under test are fitted to parts of the test data set during the development of the function, but others are not. Therefore, a structural formula comparison is made by transferring altogether 13 transport functions into a standardized notation. Although these formulas were developed from different perspectives and with different approaches, it is shown that these approaches lead to essentially the same basic formula for the main variables. These are shear stress and critical shear stress. -
A Two-Phase Flow Model of Sediment Transport: Transition from Bedload To
J. Fluid Mech. (2014), vol. 755, pp. 561–581. c Cambridge University Press 2014 561 doi:10.1017/jfm.2014.422 A two-phase flow model of sediment transport: transition from bedload to suspended load Filippo Chiodi1, Philippe Claudin1 and Bruno Andreotti1, † 1Laboratoire de Physique et Mécanique des Milieux Hétérogènes, (PMMH UMR 7636 ESPCI – CNRS – University Paris Diderot – University P. M. Curie) 10 rue Vauquelin, 75005 Paris, France (Received 7 December 2013; revised 2 May 2014; accepted 21 July 2014) The transport of dense particles by a turbulent flow depends on two dimensionless numbers. Depending on the ratio of the shear velocity of the flow to the settling velocity of the particles (or the Rouse number), sediment transport takes place in a thin layer localized at the surface of the sediment bed (bedload) or over the whole water depth (suspended load). Moreover, depending on the sedimentation Reynolds number, the bedload layer is embedded in the viscous sublayer or is larger. We propose here a two-phase flow model able to describe both viscous and turbulent shear flows. Particle migration is described as resulting from normal stresses, but is limited by turbulent mixing and shear-induced diffusion of particles. Using this framework, we theoretically investigate the transition between bedload and suspended load. Key words: alluvial dynamics, multiphase and particle-laden flows, particle/fluid flow 1. Introduction When a sedimentary bed is sheared by a water flow of sufficient strength, the particles are entrained into motion. In a homogeneous and steady situation, the fluid flow can be characterized by a unique quantity: the shear velocity u .