Flow Details near River Groynes: Experimental Investigation

Yossef, M.F.M.; Vriend, H.J. de

doi:10.1061/(asce)hy.1943-7900.0000326

Cited by 50 publications

(28 citation statements)

References 19 publications

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“…Our observations reveal that, at certain phases during the lifetime of slump blocks, the near‐bank flow field may be deflected up and over the block and toward the bank, thereby promoting erosion. In a similar way, observations have shown that flow may be deflected up and over bendway weirs and groines at certain flow stages [ Abad et al ., ; McCoy et al ., ; Bhuiyan et al ., ; Jamieson et al ., ; Yossef and de Vriend , ]. Abad et al .…”

Section: Discussionmentioning

confidence: 98%

“…Although past studies have investigated the effect of bank roughness on near‐bank flows, these have either been of insufficient spatial resolution to resolve fully the three‐dimensional flow near the bank [ Jin et al ., ; Thorne and Furbish , ], or they have documented flow associated with large‐scale roughness elements in physical experiments [ Mizumura and Yamasaka , ; McCoy et al ., , ; Yossef and de Vriend , ] and numerical models [ Mcbride et al ., ; Blanckaert et al ., , , ; Abad et al ., ], or studied the effects of artificial bend‐way weirs, wing‐dikes, and groins [ Abad et al ., ; Jamieson et al ., ]. The current absence of detailed 3‐D measurements documenting the effects of bank roughness on near‐bank flow in natural channels is partly due to the complexity and spatial scale of the processes involved and remains a significant research gap [ Motta et al ., ].…”

Section: Introductionmentioning

confidence: 99%

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Modulation of outer bank erosion by slump blocks: Disentangling the protective and destructive role of failed material on the three‐dimensional flow structure

Hackney

Best

Leyland

et al. 2015

Geophysical Research Letters

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The three‐dimensional flow field near the banks of alluvial channels is the primary factor controlling rates of bank erosion. Although submerged slump blocks and associated large‐scale bank roughness elements have both previously been proposed to divert flow away from the bank, direct observations of the interaction between eroded bank material and the 3‐D flow field are lacking. Here we use observations from multibeam echo sounding, terrestrial laser scanning, and acoustic Doppler current profiling to quantify, for the first time, the influence of submerged slump blocks on the near‐bank flow field. In contrast to previous research emphasizing their influence on flow diversion away from the bank, we show that slump blocks may also deflect flow onto the bank, thereby increasing local shear stresses and rates of erosion. We use our measurements to propose a conceptual model for how submerged slump blocks interact with the flow field to modulate bank erosion.

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Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Modulation of outer bank erosion by slump blocks: Disentangling the protective and destructive role of failed material on the three‐dimensional flow structure

Hackney

Best

Leyland

et al. 2015

Geophysical Research Letters

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“…Sequences of man-made lateral cavities, termed groyne fields, also can be found in rivers and are separated by groynes. Groynes are engineered structures comprised of either gravel, stone, earth, or piles and built at an angle to river banks to prevent bank erosion, encourage channel scouring for ship navigation, and enhance sediment storage for fish and vegetation biodiversity (Uijttewaal et al, 2001;Uijttewaal, 2005;Engelhardt et al, 2004;McCoy et al, 2007;Weitbrecht et al, 2008;Yossef and De Vriend, 2011). The flow features associated with lateral cavities are complex and vary, depending on whether the flow obstruction creating the lateral cavity is emergent or submerged.…”

Section: Lateral Cavitiesmentioning

confidence: 99%

“…3). Mass and momentum are exchanged by strong, fully three-dimensional vortical structures in the lateral mixing layer and at the water surface in the recirculation region due to the overtopping flow (Tominaga et al, 2001;Uijttewaal, 2005;Yossef and De Vriend, 2011). The overtopping flow disrupts the near-surface recirculation pattern that would otherwise occur for an emergent lateral cavity (Uijttewaal, 2005;McCoy et al, 2007).…”

Section: Submerged Lateral Cavitiesmentioning

confidence: 99%

“…At low relative submergence levels (i.e., when the ratio of main channel depth to the protruding obstruction height is small), the flow field near the water surface nearly parallels the main channel flow during an overtopping event and then returns to an emergent lateral cavity flow field between events (Uijttewaal, 2005). At higher submergence levels, the near-surface cavity flow remains nearly parallel to the main channel flow (Elawady et al, 2000;Uijttewaal, 2005;Yossef and De Vriend, 2011). The middepth and deeper regions of the recirculating flow are largely unaffected because the deeper cavity flow is driven by momentum exchange through the lateral mixing layer (Peng and Kawahara, 1997;Peng et al, 1999;McCoy et al, 2007).…”

Section: Submerged Lateral Cavitiesmentioning

confidence: 99%

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A fluid-mechanics based classification scheme for surface transient storage in riverine environments: quantitatively separating surface from hyporheic transient storage

Jackson

Haggerty

Apte

2013

Hydrol. Earth Syst. Sci.

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Abstract. Surface transient storage (STS) and hyporheic transient storage (HTS) have functional significance in stream ecology and hydrology. Currently, tracer techniques couple STS and HTS effects on stream nutrient cycling; however, STS resides in localized areas of the surface stream and HTS resides in the hyporheic zone. These contrasting environments result in different storage and exchange mechanisms with the surface stream, which can yield contrasting results when comparing transient storage effects among morphologically diverse streams. We propose a fluid mechanics approach to quantitatively separate STS from HTS that involves classifying and studying different types of STS. As a starting point, a classification scheme is needed. This paper introduces a classification scheme that categorizes different STS in riverine systems based on their flow structure. Eight STS types are identified and some are subcategorized based on characteristic mean flow structure: (1) lateral cavities (emergent and submerged); (2) protruding in-channel flow obstructions (backward-and forward-facing step); (3) isolated in-channel flow obstructions (emergent and submerged); (4) cascades and riffles; (5) aquatic vegetation (emergent and submerged); (6) pools (vertically submerged cavity, closed cavity, and recirculating reservoir); (7) meander bends; and (8) confluence of streams. The long-term goal is to use the classification scheme presented to develop predictive mean residence times for different STS using fieldmeasurable hydromorphic parameters and obtain an effective STS mean residence time. The effective STS mean residence time can then be deconvolved from the transient storage residence time distribution (measured from a tracer test) to obtain an estimate of HTS mean residence time.

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Streamflow Observations From Cameras: Large‐Scale Particle Image Velocimetry or Particle Tracking Velocimetry?

Tauro

Piscopia

Grimaldi

2017

Water Resources Research

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Image‐based methodologies, such as large scale particle image velocimetry (LSPIV) and particle tracking velocimetry (PTV), have increased our ability to noninvasively conduct streamflow measurements by affording spatially distributed observations at high temporal resolution. However, progress in optical methodologies has not been paralleled by the implementation of image‐based approaches in environmental monitoring practice. We attribute this fact to the sensitivity of LSPIV, by far the most frequently adopted algorithm, to visibility conditions and to the occurrence of visible surface features. In this work, we test both LSPIV and PTV on a data set of 12 videos captured in a natural stream wherein artificial floaters are homogeneously and continuously deployed. Further, we apply both algorithms to a video of a high flow event on the Tiber River, Rome, Italy. In our application, we propose a modified PTV approach that only takes into account realistic trajectories. Based on our findings, LSPIV largely underestimates surface velocities with respect to PTV in both favorable (12 videos in a natural stream) and adverse (high flow event in the Tiber River) conditions. On the other hand, PTV is in closer agreement than LSPIV with benchmark velocities in both experimental settings. In addition, the accuracy of PTV estimations can be directly related to the transit of physical objects in the field of view, thus providing tangible data for uncertainty evaluation.

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Flow Details near River Groynes: Experimental Investigation

Cited by 50 publications

References 19 publications

Modulation of outer bank erosion by slump blocks: Disentangling the protective and destructive role of failed material on the three‐dimensional flow structure

Modulation of outer bank erosion by slump blocks: Disentangling the protective and destructive role of failed material on the three‐dimensional flow structure

A fluid-mechanics based classification scheme for surface transient storage in riverine environments: quantitatively separating surface from hyporheic transient storage

Streamflow Observations From Cameras: Large‐Scale Particle Image Velocimetry or Particle Tracking Velocimetry?

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