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Development and installation of bedload monitoring systems with submerged load cells

Journal of Mountain Science 2016年第2期13卷 369-376页

作者： Ken GOTO Takahiro ITOH Takahiko NAGAYAMA Rei UTSUNOMIYA Daizo TSUTSUMI Takahisa MIZUYAMA Research and Development Center Nippon Koei Co.Ltd.2304 InariharaTsukubaIbaraki 300-1259Japan Nippon Koei Co. Ltd.4-2 Koji-machiChiyodaTokyo 102-0083Japan JFE Advantech Go. Ltd.3-48 Takahata-choNishinomiyaHyogo 663-8202Japan Disaster Prevention Research Institute Kyoto University436-13 NakaoOkuhidaonsengoTakayamaGifu 506-1422Japan Graduate School of Agriculture Kyoto UniversityKitashirakawa Oiwake-choSakyoKyoto 606-8502Japan

bedload governs riverbed channel variations and morphology, it is necessary to determine bedload discharge through an arbitrary cross section in a mountain fiver. A new system with submerged load cells has been developed to directly measure bedload discharge. The system consists of：（1） an iron box which is 1 m long, 0.5 m wide and 0.1 m in depth, （2） two submerged load cells 0.7 m apart, （3） a pressure sensor and, （4） an electromagnetic velocity meter. This system has been designed to exclude the effect of the hydraulic pressure of water on direct measurements of bedload particle weight. Initial tests in a laboratory were conducted to examine the accuracy of measurements with the system under aerial conditions. The system has been installed in the supercritical flume in Ashi-arai-dani River of the Hodaka Sedimentation Observatory of the Disaster Prevention Research Institute （DPRI） of Kyoto University to obtain bedload discharge under natural conditions. Flume tests were conducted in this channel by artificial supply of uniform sediment particles of several grain sizes. The average velocity of the sediment particles near the bed was estimated using cross-correlation functions for weight waves obtained by the two load cells, bedload discharge calculations were based on time integration of the product of sediment velocity and sediment weight obtained by the two load cells. This study clarifies the reasons why bedload measurements are difficult, and provides some solutions using the monitoring systems with submerged load cells through the field measurements. Additionally, the applicability of bedload measurement with the submerged load cells is explained based on experimental artificial sediment supply data.

关键词： bedload Submerged load cell Flume tests

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Application of an impact plate-bedload transport measuring system for high-speed flows

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International Journal of Sediment Research 2018年第1期33卷 35-46页

作者： Takahiro Koshiba Christian Auel Daizo Tsutsumi Sameh A.Kantoush Tetsuya Sumi Water Resources Research Center Disaster Prevention Research Institute Kyoto University ILF Consulting Engineers Hodaka Sedimentation Observatory Research Center for Fluvial and Coastal Disasters Disaster Prevention Research Institute Kyoto University

To achieve the sustainable use of dams, the development of methods for sediment management in reservoirs is required. One such method includes the use of Sediment Bypass Tunnels(SBTs) to divert sediment around a dam, thereby preventing sedimentation in the reservoir. However, SBTs are prone to severe invert abrasion caused by the high sediment flux. Therefore, it is necessary to establish a measurement system of the sediment transport rate in these tunnels. One system to measure sediment transport in rivers is the Swiss plate geophone, which can register plate vibrations caused by particle impact. In Japan, the Japanese pipe microphone is used, and sediment transport is measured based on the sound emitted by the particle impact. In this study an attempt was made to optimize the advantages of both systems by fixing a microphone and an acceleration sensor to a steel plate. The results of calibration experiments with this new system are presented and compared with the existing methods. It was found that the acceleration sensor can detect sediment particles larger than 2 mm in ***, a new parameter, referred to as the detection rate, was introduced to describe the correlation between the actual amount of sediment and the registered output. Finally, two parameters-the saturation rate and hit rate-are introduced and exhibit strong correlation with the detection rate.(?) 2018 International Research and Training Centre on Erosion and Sedimentation/the World Association

关键词： Sediment Bypass Tunnel bedload Acoustic measurement Geophone Hydrophone High-speed flow

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Near-bankfull floods in an Alpine stream:Effects on the sediment mobility and bedload magnitude

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International Journal of Sediment Research 2018年第1期33卷 27-34页

作者： Riccardo Rainato Luca Mao Lorenzo Picco Department of Land Environment Agriculture and Forestry University of Padova Department of Ecosystems and Environment Pontificia Universidad Catòlica de Chile

In a mountain environment, the transport of coarse material is a key factor for many fields such as geomorphology, ecology, hazard assessment, and reservoir management. Despite this, there have been only a few field investigations of bedload, in particular using multiple monitoring methods. In this sense,attention has frequently focused on the effects of "high magnitude/low frequency floods" rather than on "ordinary events". This study aims to analyze the sediment dynamics triggered by three high-frequency floods(recurrence interval "RI" between 1.1 and 1.7 yr) that occurred in the Rio Cordon basin during 2014. The flood events were investigated in terms of both sediment mobility and bedload magnitude. The Rio Cordon is an Alpine basin located in northeastern Italy. The catchment has a surface area of 5 km~2,ranging between 1763 and 2763 m above sea level. The Rio Cordon flows on an armored streambed layer,with a stable step-pool configuration and large boulders. Since 1986, the basin has been equipped with a permanent station to continuously monitor water discharge and sediment flux. To investigate sediment mobility, 250 PIT-tags were installed in the streambed in 2012. The 2014 floods showed a clear difference in terms of tracer displacement. The near-bankfull events showed equal mobility conditions, with mean travel distance one order of magnitude higher than the below-bankfull event. Furthermore, only the near-bankfull events transported coarse material to the monitoring station. Both events had a peak discharge up to 2.06 m~3 s, but the bedload transport rates differed by more than one order of magnitude, proving that under the current supply-limited condition, the bedload appears more related to the sediment supply than to the magnitude of the hydrological features. In this sense, the results demonstrated that near-bankfull events can mobilize large amounts of material for long distances, and that floods of apparently similar magnitude may lead to different se

关键词： bedload Alpine basin Sediment dynamics bedload tracing PIT-tags

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Numerical simulation of hydrodynamic characteristics and bedload transport in cross sections of two gravel-bed rivers based on one-dimensional lateral distribution method

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International Journal of Sediment Research 2020年第2期35卷 203-216页

作者： Chien Pham Van Vivien Chua Department of River Engineering and Disaster Management Faculty of Hydrology and Water ResourcesThuyloi University Unite de Mod'elisation Mathematiques et Informatiquedes Systemesco Complexes (UMMISCO) JEAI WARMIRDSorbonne Universit'e Department of Civil and Environmental Engineering Faculty of EngineeringNational University of Singapore

Accurate evaluation and prediction of bedload transport are crucial in studies of fluvial hydrodynamic characteristics and river *** paper presents a one-dimensional numerical model based on the one-dimensional lateral distribution method(1 D-LDM) and six classic bedload transport formulae that can be used to simulate hydrodynamic characteristics and bedload transport discharge in cross *** gravel-bed rivers,*** Danube River located approximately 70 km downstream from Bratislava in Slovakia and the Tolten River in south of Chile are used as *** the 1 D-LDM,gravity,bed shear stress,turbulent diffusion,and secondary flow are included to allow for accurate predictions of flow velocity and consequently bed shear stress in the cross *** classic formulae were applied to evaluate the non-dimensional bedload transport rate,and the bedload transport discharge through a river cross section is obtained by integrating the bedload transport rate over the width of the cross *** results show that the root mean square error(RMSE) and mean absolute error(MAE) of velocity and water discharge were less than 8% of the observed magnitude,while the correlation coefficient between model predictions and observations was close to *** formulae proposed by Ashida and Michiue(1972),in which particle collision with the bed is taken into account,and by Camenen and Larson(2005),which allows for yielding a non-zero bedload transport rate even when the bed shear stress is smaller than the critical bed shear stress value,appeared to be more appropriate for predicting the observed bedload transport rate in the studied cross sections of two gravel-bed *** non-uniform sediment mixtures were considered,the bedload transport discharge through a cross-section could change considerably by up to 22.5% of the observed *** relations proposed by Ashida and Michiue(1972) and Egiazaroff(1965) for parameterizing the hiding factor yielded more

关键词： bedload Gravel-bed river One-dimensional lateral distribution method bedload transport discharge

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On the mechanisms of the saltating motion of bedload

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International Journal of Sediment Research 2017年第1期32卷 53-59页

作者： Youhua Chen Yuchuan Bai Dong Xu State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Jinchang Water Conservancy Department

Saltation of sediment particles is an important pattern of bedload *** on force analysis for sediment particles,a Lagrangian model was proposed for the saltating motion of bedload in river flows,which was then solved with numerical *** results on the saltating trajectories neglecting particle rotation and turbulence effects compare fairly well with experimental *** mean values of the saltation parameters(saltation height,length and velocity) also agree well with the previous experimental *** on the numerical results,regression equations for the dimensionless saltation height,length and velocity were *** the numerically achieved characteristics of the sediment saltation,we also obtained mathematical expression for the sediment transport *** studies in this paper are significant for its contribution to mechanism of the bedload motion and the computation of sediment transport rate.

关键词： bedload Saltation Numerical model Transport rate

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COORDINATION OF INTERNATIONAL bedload RESEARCH

COORDINATION OF INTERNATIONAL BEDLOAD RESEARCH

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第九次河流泥沙国际学术大会

作者： John R.GRAY Jonathan B.LARONNE U.S. Geological Survey Reston Virginia U.S.A. 20192. The Ben Gurion University of the Negev Beer Sheva 84105 Israel.

＜正＞The state of the science of bedload research and monitoring in the last quarter century has progressed at a much slower rate than that for suspended sediment due to a number of constraints. Most traditional devices still entail routine collection and subsequent analyses of physical samples. The amount and reliability of the bedload data remain limited by the characteristics of the collecting instrument, vagaries associated with manual deployment, a lack of temporal continuity in measurements, and hydraulic and bed conditions. Acceptable and quantifiably accurate measurement of bedload discharge at discrete time intervals, let alone as a time series, is rarely an attainable goal. The accuracy of equations for estimating bedload transport, predicated on data reliability, remains unquantifiable for most conditions. On-going research on bedload-measurement instruments and measuring techniques has been taking place on an ad hoc basis within and between various countries, with little coordination among researchers. bedload studies often lack adequate funding and adequate local or institutional scientific support. We propose establishing a bedload Research International Cooperative （BRIC） to address some of these constraints. The BRIC would be by, for, and responsive to the international bedload research and monitoring community. It would provide an international focal point for bedload research, methods development and data sharing. Membership would be free, as would be acquisition of BRIC data. Information compiled and disseminated as part of the BRIC would enable coordination of research to fill critical gaps in our knowledge of bedload processes and measurement techniques. The concept of the BRIC is evolving;suggestions are sought as the concept matures.

关键词： bedload bedload monitoring bedload research International collaboration

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CHARACTERISTICS OF bedload DISTRIBUTION - CHANGJIANG ESTUARY, CHINA

CHARACTERISTICS OF BEDLOAD DISTRIBUTION - CHANGJIANG ESTUARY...

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第九次河流泥沙国际学术大会

作者： Hong LIU Qing HE and Yi MENGState key Lab of Estuarine and Coastal Research ECNU Shanghai 200062 China

＜正＞Picture of bedload grain size distribution was drawn based on 52 samples collected in Feb. 2003. Results show that the major bedload sediment of the estuary is made up of clayey silt, silt, sandy silt and sand. Most of the bedload grain size is finer gradually from inside of the estuary to the outside except the North Branch, and the particle diameter ranges from 0.005mm to 0.223mm. By the influence of salt water intruding, the bedload sediment of the North Branch mainly comes from the sea out of the estuary and the sediment resuspension.

关键词： Changjiang Estuary bedload Particle Diameter Distribution Characteristics

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Experimental investigation of sediment transport in partially ice-covered channels

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International Journal of Sediment Research 2023年第5期38卷 769-779页

作者： Mina Rouzegar Shawn P.Clark Department of Civil Engineering University of Manitoba

It is important to understand the effects of ice cover on sediment transport in cold climates, where subfreezing temperatures affect water bodies for a significant part of the year. The literature contains many studies on sediment transport in open channel flow, and several studies on sediment transport in completely ice-covered flow. There has been little or no research on sediment transport in partially icecovered channels. In the current study, laboratory experiments were done in a rectangular flume to quantify the impact of border ice presence on the sediment transport rate. The effects of ice cover extent and changing flow strengths on sediment transport distribution also were investigated, and the results were compared to those for fully ice-covered and open channel flow. The ice coverage ratios considered were 0(representing the open water condition), 0.25, 0.50, 0.67, and 1(representing fully ice-covered flow). The partial ice cover was found to impact the sediment transport distribution within the channel. The effect of ice coverage extent on sediment transport distribution was more significant at lower flow strengths and became negligible at higher flow strengths. The conventional equations for sediment transport in open channel flow and fully ice-covered flow that relate the dimensionless bedload transport rate to the flow strength were found to be applicable to estimate the total cross-section-averaged bedload transport for partially ice-covered flow when modified appropriately. Empirical coefficients for these equations were determined using the experimental data.

关键词： Sediment transport bedload Ice-covered channel Border ice

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Numerical modelling of riverbed grain size stratigraphic evolution

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International Journal of Sediment Research 2014年第3期29卷 329-343页

作者： Peng HU Zhi-xian CAO Gareth PENDER Huai-han LIU Ocean College Zhejiang University State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Institute for Infrastructure and Environment Heriot-Watt University Institute for Infrastructure and Environment Heriot-Watt University State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Yangtze Waterway Planning Design and Research Institute

For several decades,quantification of riverbed grain size stratigraphic evolution has been based upon the active layer formulation(ALF),which unfortunately involves considerable *** it is the sediment exchange across the bed surface that directly affects the riverbed stratigraphy,it has been assumed in the ALF that the sediment fraction at the lower interface of the active layer is a linear function of the sediment fraction in the *** it is proposed that the sediment fraction of the sediment exchange flux is used directly in estimating the sediment fraction at the lower surface of the active *** with the size-specific mass conservation for riverbed sediment,the modified approach is referred to as the surface-based formulation(SBF).When incorporated into a coupled non-capacity modelling framework for fluvial processes,the SBF leads to results that agree as well or better than those using ALF with laboratory and field *** is illustrated for typical cases featuring bed aggradation and degradation due to graded bed-load sediment *** experiments on graded sediment transport by unsteady flows are warranted for further testing the modified formulation.

关键词： bedload Riverbed grain size stratigraphy Active layer formulation Surface-based formulation Numerical modelling

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Contrasting lipid biomarkers in mountain rivers in the Nepal Himalayas: Organic matter characteristics and contribution to the fluvial carbon pool

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Geoscience Frontiers 2021年第6期12卷 1-15页

作者： Rajendra Bhandari Joyanto Routh Subodh Sharma Rajendra Joshi Department of Thematic Studies–Environmental Change Linköping UniversitySweden Aquatic Ecology Center Kathmandu UniversityNepal Department of Environmental Science and Engineering Kathmandu UniversityNepal Department of Chemical Science and Engineering Kathmandu UniversityNepal

The Nepal Himalayas is the source of many glacial and spring-fed river systems crisscrossing the mountainous *** is an increasing recognition of small mountain rivers(SMRs)to have a significant combined export of dissolved and particulate organic carbon to the global carbon *** analyzed fluvial sediments from two SMRs and compared the results with two large mountain rivers(LMRs)in *** investigated the organic matter(OM),its compositional variability,and seasonal export using a suite of lipid biomarkers,namely n-alkanes,n-alkanoic acids,n-alkanols,and *** SMRs indicated a similarity in lipid distribution and were affected by a strong seasonal *** LMRs showed a distinct contrast in the distribution of lipids in suspended *** sediments in SMRs were derived from diverse sources with weak terrigenous dominance all-year-round compared to the suspended *** lipids(n-alkanoic acids and n-alkanols)were the major constituents in SMR sediments,indicating better *** contrast,n-alkane concentration dominated over other fractions in suspended sediments retrieved from *** biomarker trends differentiate SMRs from LMRs with lower transformed/degraded OM in SMRs.A common observation was the strong presence of even carbon compounds in short-chain n-alkanes in SMR bedload sediments and their predominance in suspended sediments in *** an unusual trend is attributed to specific biomarker sources from the catchment and ongoing processes in fluvial *** colonized by fungal species under moist acidic conditions and autochthonous bacteria contributes to the organic matter pool in shallow *** LMRs,the contribution from thermally mature sedimentary hydrocarbons and the diagenetic reduction of nalkanoic acids to n-alkanes are additional contributors to the allochthonous carbon *** differences in lipid concentrations,their distribution,seasonality,and the size of rivers suggest differential

关键词： Fluvial sediments bedload Suspended load Monsoon Biomarkers Biogeochemistry

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