Scour Problems Downstream of Low-Head Hydraulic Structures

Pagliara, Stefano; Palermo, Michele

doi:10.1007/978-3-319-17719-9_4

Cited by 4 publications

(2 citation statements)

References 26 publications

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“…Thus, expensive and inefficient fish ladders, which are usually built with more traditional hydraulic structures spanning river channels, are not required. Block ramp structures have been extensively investigated in recent years, both in the field and in hydraulic laboratories, as both physical and numerical models [20,[27][28][29][30][31][32]. Block ramps are environmentally friendly, low-head hydraulic structures that mimic natural river rapids, allowing fish and invertebrates to migrate [33] and, at the same time, are engineering structures that stabilize river and stream beds.…”

Section: Introductionmentioning

confidence: 99%

Bed Load Transport and Alternation of a Gravel-Bed River Morphology within a Vicinity of Block Ramp: Classical and Numerical Approach

et al. 2022

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In current river management, we very often use environment-friendly hydraulic structures when it is required for river bed or river bank protection due to erosion of a river channel. Block ramps are one of many methods used to stabilize river beds. They provide a semi-natural solution to certain river engineering problems in mountain streams. When building block ramps, one can use the dissipative behavior of large rock blocks or boulder elements randomly placed on the river bed to enhance fish migration in an upstream direction; thus, they can serve as fish passes. In this paper, we present the results of the numerical modelling of a bed load transport and the morphological changes of a river bed where a block ramp was designed and built. The main aim of the study was to investigate the difference of 2D modelling of a bed load transport along the mountain stream reach with boulder ramps in comparison to the classical methods of Hjulström, Shields, and Russian standard ST-24-2396. The work was carried out on the stream of one of the chosen low-head hydraulic structures, where 25 identical block ramps were constructed for river training reasons. The novel approach of our study is, for the first time in the field, to show a very detailed analysis of block ramp influence on sediment transport and river morphology changes compared to the classical understanding of those phenomena, as well as 2D model results to give hydraulic engineers an inside look into classical and modern approaches of bed load transport calculations. This might be helpful for designing such kinds of hydraulic structures in the future, in all regions where sediment transport calculations are important but do not always require sophisticated modelling.

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Section: Introductionmentioning

confidence: 99%

Bed Load Transport and Alternation of a Gravel-Bed River Morphology within a Vicinity of Block Ramp: Classical and Numerical Approach

et al. 2022

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“…There are many operational and emerging methods for waterway gauging, varying widely in cost, accuracy, reliability, and risk (Tauro et al, 2018;Gordon, 1989;Costa et al, 2000;Tauro et al, 2016;Yang et al, 2020). Intrusive methods range from the resource intensive installation of hydraulic control structures to measure discharge rates analytically using simpler water level measurements within a designed range by obstructing and controlling the flow through a standardised geometry (Boiten, 2002) (often to the detriment of aquatic species (Mueller et al, 2011), as well as sedimentation and erosion (Pagliara and Palermo, 2015;Ogden et al, 2011)), through to the risking of people and equipment entering the stream to measure velocities using passive mechanical current meters or active acoustic doppler velocimetry profiles (Gordon, 1989).…”

mentioning

confidence: 99%

Adaptively monitoring streamflow using a stereo computer vision system

Hutley

Beecroft²,

Wagenaar³

et al. 2022

Preprint

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Abstract. The gauging of free surface flows in waterways provides the foundation for monitoring and managing the water resources of built and natural environments. A significant body of literature exists around the techniques and benefits of optical surface velocimetry methods to estimate flows in waterways without intrusive instruments or structures. However, to date the operational application of these surface velocimetry methods has been limited by site configuration and inherent challenging optical variability across different natural and constructed waterway environments. This work demonstrates a significant advancement in the operationalisation of non-contact stream discharge gauging applied in the computer vision stream gauging (CVSG) system through the use of methods for remotely estimating water levels and adaptively learning discharge ratings over time. A cost-effective stereo camera-based stream gauging device (CVSG device) has been developed for streamlined site deployments and automated data collection. Evaluations between reference state-of-the-art discharge measurement technologies using DischargeLab (using surface structure image velocimetry), Hydro-STIV (using space-time image velocimetry), ADCPs (acoustic doppler current profilers), and gauging station discharge ratings demonstrated that the optical surface velocimetry methods were capable of estimating discharge within best available measurement error margins of 5–15 %. Furthermore, results indicated model machine learning approaches leveraging data to improve performance over a period of months at the study sites produced a marked 5–10 % improvement in discharge estimates, despite underlying noise in stereophotogrammetry water level or optical flow measurements. The operationalisation of optical surface velocimetry technology, such as CVSG, offers substantial advantages towards not only improving the overall density and availability of data used in stream gauging, but also providing a safe and non-contact approach for effectively measuring high flow rates while providing an adaptive solution for gauging streams with non-stationary characteristics.

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The effect of tetrahedron framed permeable weirs on river bed stability in a mountainous area under clear water conditions

Wang

Yang

Zhou

et al. 2017

Sci Rep

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A flexible riverbed protection called tetrahedron framed permeable weirs (TFPW) is proposed to protect riverbeds in mountainous areas from scouring. Under clear water conditions, a series of laboratory flume experiments were performed to study the effects of TFPW with different layout types on the stability of riverbeds. The objectives of this paper were to advance understanding of the role that TFPW play in the erosion process of river beds and to optimize the TFPW design for reducing velocity, promoting sediment deposition and good structural stability. Data on velocity distribution and variation, equilibrium bathymetry, flow resistance, bed form characteristics and structural stability were collected and analyzed. The results indicate that (1) with good structural stability, all the TFPW with different layout types had significant effects on the stabilization of the riverbed by reducing velocity, raising the water level, increasing the roughness coefficient, protecting the riverbed from degradation and promoting deposition; and (2) the random Double TFPW with large rates of deceleration, large deposition ranges, and good structural stability, and the paved Single TFPW with small rates of deceleration but large deposition ranges and perfect structural stability, were suitable and optimal for riverbed protection in a clear water channel.

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Scour Problems Downstream of Low-Head Hydraulic Structures

Cited by 4 publications

References 26 publications

Bed Load Transport and Alternation of a Gravel-Bed River Morphology within a Vicinity of Block Ramp: Classical and Numerical Approach

Bed Load Transport and Alternation of a Gravel-Bed River Morphology within a Vicinity of Block Ramp: Classical and Numerical Approach

Adaptively monitoring streamflow using a stereo computer vision system

The effect of tetrahedron framed permeable weirs on river bed stability in a mountainous area under clear water conditions

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