scholarly journals Flow dynamics and bedload sediment transport around paired deflectors for fish habitat enhancement: a field study in the Nicolet River

2007 ◽  
Vol 34 (6) ◽  
pp. 761-769 ◽  
Author(s):  
David M Carré ◽  
Pascale M Biron ◽  
Susan J Gaskin
Keyword(s):  
Sediment Transport ◽  
Radio Frequency Identification ◽  
Fish Habitat ◽  
Sediment Traps ◽  
Bedload Transport ◽  
Flow Dynamics ◽  
Left Bank ◽  
Passive Integrated Transponder ◽  
Bedload Sediment ◽  
The Impact

Schemes to restore fish habitat in rivers often involve installing instream structures such as current deflectors to create and maintain riffle-pool sequences. However, there is a lack of field studies on the impact of these structures on flow dynamics and bed topography. The objective of this research is to characterize flow dynamics and sediment transport around paired deflectors used to enhance fish habitat in the Nicolet River, Quebec. Bed and bank topography surveys were taken with a total station, and velocity and bed shear stress estimates were obtained from an acoustic doppler velocimeter. Bedload sediment transport was assessed by two methods: tracer rocks (painted "particles" and passive integrated transponder tags) and sediment traps. Results show marked differences in bedload sediment transport patterns between the left bank and the right bank downstream of the deflectors. This is surprising considering that paired deflectors should produce a relatively symmetrical disruption to the flow field on each side. More high-flow dynamics data during overtopping conditions are required to understand the complex interactions between these instream structures and bedload transport. Key words: stream restoration, pool, bedload transport, radio frequency identification (RFID), passive integrated transponder (PIT) tags, fieldwork, deflectors, fish habitat.

The impact of hydropeaking on sediment transport

2021 ◽  
Author(s):  
Daniel Buček ◽  
Martin Orfánus ◽  
Peter Dušička ◽  
Peter Šulek
Keyword(s):  
Sediment Transport ◽  
Renewable Energy Sources ◽  
Field Measurements ◽  
Bedload Transport ◽  
Hydropower Plant ◽  
Energy Sources ◽  
Hydropower Plants ◽  
Daily Scale ◽  
Flexible Management ◽  
The Impact

AbstractVariable renewable energy sources, e.g. solar and wind power, require flexible management of energy sources to stabilize the power grid. Immediate changes in power generation and power usage is compensated for by the operation of hydropower plants. This subsequently leads to frequent flow fluctuations – hydropeaking downstream of the hydropower plant. This study examines the short-term impacts of hydropeaking of hydropower plants on the sediment transport using numerical morphodynamic model. The model is calibrated to field measurements and subjected to various hydropeaking scenarios on daily to sub-daily scale. Based on this study, the effect of hydropeaking of hydropower plant 23.42 km upstream of the studied river section would have negligible effect on the bedload transport in the studied cross section.

scholarly journals SewerSedFoam: A Model for Free Surface Flow, Sediment Transport, and Deposited Bed Morphology in Sewers

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 270 ◽  
Author(s):  
Madhu K Murali ◽  
Matthew R Hipsey ◽  
Anas Ghadouani ◽  
Zhiguo Yuan
Keyword(s):  
Free Surface ◽  
Sediment Transport ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Bedload Transport ◽  
Sediment Deposition ◽  
Suspended Sediment Transport ◽  
Flow Solver ◽  
Bed Morphology ◽  
Bedload Sediment

This paper aims to bridge the gap in the detailed modelling of flow and sediment process interactions in sewers through the development of a computational fluid dynamics (CFD) model. It draws on previous models developed for surface water sediment transport in the OpenFOAM CFD framework and builds on them to improve their suitability for sewer sediment processes. Three distinct sediment processes, suspended sediment transport, bedload transport, and deposited bed morphology, are incorporated into a free surface flow solver, interFoam. This sewer sediment model, called SewerSedFoam, models the impacts of sediment deposition and erosion on flow velocity by using dynamic mesh deformation to capture the movement of the deposited bed and its morphology. Further, three sediment classes, two suspended and one bedload sediment, can be modelled along with some bed stabilization and consolidation effects during deposition and erosion, respectively. The functionality of the overall model in modelling sewer sediment deposition and erosion is promising, although the validation of a large magnitude sediment erosion event has been limited by the availability of granular data in existing case studies.

scholarly journals Bedload Sediment Transport in Connection with the Geomorphological Transition of Gravel-Bed Streams in the Moravskoslezské Beskydy Mountains

Geografie ◽  
2012 ◽  
Vol 117 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Tomáš Galia ◽  
Václav Škarpich ◽  
Jan Hradecký
Keyword(s):  
Sediment Transport ◽  
Cross Sections ◽  
Bedload Transport ◽  
High Rate ◽  
Stream Power ◽  
Empirical Formulas ◽  
Fluvial Erosion ◽  
Gravel Bed ◽  
Bedload Sediment ◽  
Gravel Bed Streams

This paper summarizes the results of bedload transport research in the Morávka, Mohelnice and Ostravice basins, conducted using the BAGS (Bedload Assessment for Gravel-bed Streams) spreadsheet-based program and unit stream power empirical formulas. The presented results only show the potential rate of bedload transport, because sediment inputs and barriers were not included in the model. Trends in the potential bedload transport rate represent a good instrument for identifying the range of disconnected sediment transport along the longitudinal profile. Modelling on cross-sections with a high rate of fluvial erosion shows an increase in potential bedload transport and larger diameters of the largest possible transported particles, calculated using unit stream power empirical formulas. The results may be applied to improve local watershed management.

Monitoring bedload sediment transport in a pre-Alpine river: an experimental method

2017 ◽  
Vol 43 ◽  
pp. 57-63 ◽  
Author(s):  
Monica Papini ◽  
Vladislav Ivov Ivanov ◽  
Davide Brambilla ◽  
Diego Arosio ◽  
Laura Longoni
Keyword(s):  
Sediment Transport ◽  
Experimental Method ◽  
Alpine River ◽  
Bedload Sediment

scholarly journals The intensity of slope and fluvial processes after a catastrophic windthrow event in small catchments in the Tatra Mountains

2021 ◽  
Vol 18 (6) ◽  
pp. 1405-1423
Author(s):  
Dariusz Strzyżowski ◽  
Elżbieta Gorczyca ◽  
Kazimierz Krzemień ◽  
Mirosław Żelazny
Keyword(s):  
Environmental Changes ◽  
Bedload Transport ◽  
Strong Wind ◽  
Tatra Mountains ◽  
Salvage Logging ◽  
Fluvial Processes ◽  
Wind Events ◽  
And Control ◽  
The Tatra Mountains ◽  
The Impact

AbstractStrong wind events frequently result in creating large areas of windthrow, which causes abrupt environmental changes. Bare soil surfaces within pits and root plates potentially expose soil to erosion. Absence of forest may alter the dynamics of water circulation. In this study we attempt to answer the question of whether extensive windthrows influence the magnitude of geomorphic processes in 6 small second- to third-order catchments with area ranging from 0.09 km2 to 0.8 km2. Three of the catchments were significantly affected by a windthrow which occurred in December 2013 in the Polish part of the Tatra Mountains, and the other three catchments were mostly forested and served as control catchments. We mapped the pits created by the windthrow and the linear scars created by salvage logging operations in search of any signs of erosion within them. We also mapped all post-windthrow landslides created in the windthrow-affected catchments. The impact of the windthrow on the fluvial system was investigated by measuring a set of channel characteristics and determining bedload transport intensity using painted tracers in all the windthrow-affected and control catchments. Both pits and linear scars created by harvesting tend to become overgrown by vegetation in the first several years after the windthrow. The only signs of erosion were observed in 10% of the pits located on convergent slopes. During the period from the windthrow event in 2013 until 2019, 5 very small (total area <100 m2) shallow landslides were created. The mean distance of bedload transport was similar (t-test, p=0.05) in most of the windthrow-affected and control catchments. The mapping of channels revealed many cases of root plates fallen into a channel and pits created near a channel. A significant amount of woody debris delivered into the channels influenced the activity of fluvial processes by creating alternating zones of erosion and accumulation.

scholarly journals A Framework for Assessing the Value of RFID Implementation by Tier-One Suppliers to Major Retailers

2008 ◽  
Vol 3 (1) ◽  
pp. 55-70
Author(s):  
Dharmaraj Veeramani ◽  
Jenny Tang ◽  
Alfonso Gutierrez
Keyword(s):  
Supply Chain ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Return On Investment ◽  
Real Life ◽  
Data Capture ◽  
Automatic Identification ◽  
Rfid Technology ◽  
Frequency Identification ◽  
The Impact

Radio frequency identification (RFID) is a rapidly evolving technology for automatic identification and data capture of products. One of the barriers to the adoption of RFID by organizations is difficulty in assessing the potential return on investment (ROI). Much of the research and analyses to date of ROI in implementing RFID technology have focused on the benefits to the retailer. There is a lack of a good understanding of the impact of RFID at upper echelons of the supply chain. In this paper, we present a framework and models for assessing the value of RFID implementation by tier-one suppliers to major retailers. We also discuss our real-life application of this framework to one of Wal-Mart’s top 100 suppliers

Development of Model for Acoustic Noise Generated from Bedload in Rivers 

2021 ◽  
Author(s):  
Mohamad Nasr ◽  
Thomas Geay ◽  
Sébastien Zanker ◽  
Recking Alain
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Impact Velocity ◽  
Acoustic Noise ◽  
Acoustic Power ◽  
Bedload Transport ◽  
Empirical Formulas ◽  
Impact Rate ◽  
Flux Measurements ◽  
The Impact

&lt;p&gt;Quantifying bedload transport is important for many applications such as river management and hydraulic structures protection. Bedload flux measurements can be achieved using physical sampler methods. However, these methods are expensive, time-consuming, and difficult to operate during high discharge events. Besides, these methods do not permit to capture the spatial and temporal variability of bedload transport flux. Recently, alternative measuring technologies have been developed to continuously monitor bedload flux and grain size distribution using passive or active sensors. Among them, the hydrophone was used to monitor bedload transport by recording the sounds generated by bedload particles colliding on the river bed (referred as self-generated noise SGN). The acoustic power of SGN was correlated with bedload flux in field experiments. To better understand these experimental results and to estimate measurement uncertainties, we developed a theoretical model to simulate the SGN. The model computes an estimation of the power spectral density (PSD)by considering the contribution of all signals generated by impacts between bedload particles and the riverbed, and accounting for the attenuation of the acoustic signal between the source and the hydrophone position due to river propagation effects,. In this model, we&lt;/p&gt;&lt;p&gt;The energy of acoustic noise generated from the collision between two particles is mainly dependent on the transported particles' diameter and the impact velocity. We tested different empirical formulas for the estimation of the number of impact (impact rate) and the impact velocity depending on particle size and hydraulic conditions. To characterize the acoustic power losses as a function of distance and frequency, we used an attenuation function which was experimentally calibrated for different French rivers.&lt;/p&gt;&lt;p&gt;We tested the model on a field dataset comprising acoustic and bedload flux measurements. The results indicate that the PSD model allows estimating acoustic power (in between a range of one order of magnitude) for most of the rivers considered.&amp;#160; The model sensitivity was evaluated. In particular, we observed that it is very sensitive to the empirical formulas used to determine the impact rate and impact speed. In addition, special attention should be kept in mind on the assumption of the grain size distribution of riverbed which can generate large variability in some rivers particularly in rivers with a significant sand fraction.&lt;/p&gt;

scholarly journals The impact of storms and stratification on sediment transport in the Rhine region of freshwater influence

2017 ◽  
Vol 122 (5) ◽  
pp. 4456-4477 ◽  
Author(s):  
Raúl P. Flores ◽  
Sabine Rijnsburger ◽  
Alexander R. Horner-Devine ◽  
Alejandro J. Souza ◽  
Julie D. Pietrzak
Keyword(s):  
Sediment Transport ◽  
Freshwater Influence ◽  
The Impact
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