scholarly journals Multislot Fishway Improves Entrance Performance and Fish Transit Time over Vertical Slots

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 275
Author(s):  
Filipe Romão ◽  
Ana L. Quaresma ◽  
José M. Santos ◽  
Susana D. Amaral ◽  
Paulo Branco ◽  
...  
Keyword(s):  
Transit Time ◽  
Reynolds Shear Stress ◽  
Cost Effective ◽  
Fish Passage ◽  
Entrance Time ◽  
Trade Offs ◽  
Vertical Slot ◽  
Longitudinal Connectivity ◽  
Water Uses ◽  
Entry Efficiency

Pool-type fishways have been increasingly tested to improve fish passage performance and minimize migration delays. Designing cost-effective fishways is essential for a trade-off between water uses and successful longitudinal connectivity restoration. The multislot fishway (MSF) concept, which operates with 30–50% lower discharge than a vertical slot fishway (VSF), was recently developed. This study assessed and compared the entrance performance (entrance time; entry efficiency) and transit times of two cyprinids for VSFs and MSFs. Four configurations, with the same structural characteristics (slope; water depth; head drop; pool width and depth), operating with different discharges (Q), were tested (VSF 1: Q = 112 L·s−1; VSF 2: Q = 80 L·s−1; MSF 1: Q = 58 L·s−1; MSF 2: Q = 37 L·s−1). Hydrodynamics characterization was performed using a numerical model. Results showed that entry efficiency was higher in MSFs than in VSFs, while entrance time and transit time were overall lower. Numerical modelling revealed that velocities were around 30% lower in MSFs, and turbulence could reach a difference of around 70% in Reynolds shear stress and 50% in turbulent kinetic energy. Overall, MSFs can be considered as a cost-effective fishway solution that can balance the trade-offs between divergent interests in water uses.

Cyprinid passage performance in an experimental multislot fishway across distinct seasons

2019 ◽  
Vol 70 (6) ◽  
pp. 881 ◽  
Author(s):  
Filipe Romão ◽  
Ana L. Quaresma ◽  
José M. Santos ◽  
Paulo Branco ◽  
António N. Pinheiro
Keyword(s):  
Fish Community ◽  
Woody Debris ◽  
Cost Effective ◽  
Ecological Traits ◽  
Vertical Slot ◽  
Longitudinal Connectivity ◽  
Vertical Slot Fishway ◽  
Iberian Chub ◽  
Effective Design ◽  
Entry Efficiency

New engineering solutions are required to minimise the effects of an increasing number of anthropogenic barriers on watercourses. Longitudinal connectivity must be provided through fishways to allow free passage for the whole fish community. Recently, a multislot fishway (MSF) was developed, with two consecutive vertical slots that divide the overall head drop by two, thus reducing the flow velocity, the magnitude of turbulence and operational discharge compared with a standard vertical slot fishway (VSF) with similar pool and slot dimensions. The present study assessed the effectiveness of a MSF design for two cyprinid species with different ecological traits, under laboratory conditions, namely the Iberian barbel (Luciobarbus bocagei), a large-bodied potamodromous benthic fish, and the southern Iberian chub (Squalius pyrenaicus), a small-bodied water column fish. Experiments were conducted in a full-scale experimental fishway, in spring and autumn. Results showed differences in passage performance between seasons and species. During spring, chub had a higher entry efficiency and shorter transit time to fully negotiate the fishway, whereas no seasonal differences were found for the barbel. Overall, the MSF could be considered a cost-effective design for cyprinids with different ecological traits because it offers lower operational costs than a standard VSF. However, concerns about the entrance and attraction conditions should be addressed. In addition, because of the lower operational discharge, the propensity for obstruction with woody debris and sediments should not be disregarded.

scholarly journals Passage Performance of Technical Pool-Type Fishways for Potamodromous Cyprinids: Novel Experiences in Semiarid Environments

2019 ◽  
Author(s):  
Francisco J. Sanz-Ronda ◽  
Francisco J. Bravo-Córdoba ◽  
Ana Sánchez-Pérez ◽  
Ana García-Vega ◽  
Jorge Valbuena-Castro ◽  
...  
Keyword(s):  
Fish Passage ◽  
Swimming Behavior ◽  
Fish Migration ◽  
Pit Tag ◽  
Semiarid Environments ◽  
Vertical Slot ◽  
Longitudinal Connectivity ◽  
The World ◽  
Migration Pathways ◽  
Pool Type

Endemic freshwater fish from semiarid environments are among the most threated species in the world due to the water overexploitation and habitat fragmentation problems. Stepped or pool-type fishways are used worldwide to reestablish longitudinal connectivity and mitigate fish migration problems. Many of them are being installed or planned in rivers of semiarid environments, however, very few studies about fish passage performance through pool-type fishways has been carried out to date on these regions. The present work focuses on the passage performance of two potamodromous cyprinids endemic of these regions, with different ecological and swimming behavior: southern Iberian barbel (Luciobarbus sclateri) and Iberian straight-mouth nase (Pseudochondrostoma polylepis), in two of the most common types of stepped fishways: vertical slot and submerged notch with bottom orifice fishways. Experiments were carried out during the spawning season in the Segura River (South-Eastern Spain), using a PIT tag and antennas system. Ascent success was greater than 80%, with a median transit time lower than 17 minutes per meter of height in all trials and for both species and fishway types. Results show that both types of fishways, if correctly designed and built, provide interesting alternatives for the restoration of fish migration pathways on these regions.

scholarly journals Design and Function Monitoring of an Enature® Vertical Slot Fish Pass in a Large Potamal River in Carinthia/Austria

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 551 ◽  
Author(s):  
Helmut Mader ◽  
Andreas Brandl ◽  
Sabine Käfer
Keyword(s):  
Power Plant ◽  
Ecological Status ◽  
Fish Passage ◽  
Ecological Effect ◽  
Survey Method ◽  
Hydro Power ◽  
Pass System ◽  
Fish Pass ◽  
Vertical Slot ◽  
Longitudinal Connectivity

To establish good ecological status in European rivers, firstly there is the question of how to re-establish unhindered migration for fish at barriers. This article documents a project to re-establish longitudinal connectivity at a large epipotamal river at the Schwabeck Hydro Power Plant, Carinthia/Austria, from the selection of an appropriate fish pass system to the final function control. Instead of a standard vertical slot, the innovative enature® fish pass shape with a significant reduction of flow, velocities, energy dissipation rate, and turbulences, but with a clear enhancement of fish passage capability, was chosen. Using 2D hydraulic modelling and a statistical evaluation of fish passage, physical and ecological effects were reviewed, with the clear result that there is no identifiable, positive ecological effect on the number of fish migrating with an increase of concurrent flow in the fish pass. Passability and findability were monitored with the new FishCam, an automatic, precise, and constant (24/7 24 h a day, seven days a week) collection and pre-evaluation field data survey method which does not involve trapping of, contact with, or stress for fish. It was shown that the enature® fish pass enables an unhindered migration for all available fish species. As >99% of fish migrate from April to November, there is no ecological need to operate a fully functional fish pass year-round. Combining all the individual factors together, the fish pass at the Schwabeck Hydro Power Plant is an almost exemplary solution for a fully functioning restauration of the continuum with a minimized loss of generation of electricity.

scholarly journals Passage Performance of Technical Pool-Type Fishways for Potamodromous Cyprinids: Novel Experiences in Semiarid Environments

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2362 ◽  
Author(s):  
Sanz-Ronda ◽  
Bravo-Córdoba ◽  
Sánchez-Pérez ◽  
García-Vega ◽  
Valbuena-Castro ◽  
...  
Keyword(s):  
Fish Passage ◽  
Antenna System ◽  
Fish Migration ◽  
Pit Tag ◽  
Passive Integrated Transponder ◽  
Semiarid Environments ◽  
Vertical Slot ◽  
Longitudinal Connectivity ◽  
Migration Pathways ◽  
Pool Type

Endemic freshwater fish from semiarid environments are among the most threated species in the world due to water overexploitation and habitat fragmentation problems. Stepped or pool-type fishways are used worldwide to reestablish longitudinal connectivity and mitigate fish migration problems. Many of them are being installed or planned in rivers of semiarid environments, however, very few studies about fish passage performance through pool-type fishways has been carried out to date on these regions. The present work focuses on the passage performance of two potamodromous cyprinids endemic of these regions, with different ecological and swimming behavior: southern Iberian barbel (Luciobarbus sclateri) and Iberian straight-mouth nase (Pseudochondrostoma polylepis). These are assessed in two of the most common types of stepped fishways: vertical slot and submerged notch with bottom orifice fishways. Experiments were carried out during the spawning season in the Segura River (southeastern Spain), using a passive integrated transponder (PIT) tag and antenna system. Ascent success was greater than 80%, with a median transit time lower than 17 minutes per meter of height in all trials, and for both species and fishway types. Results show that both types of fishways, if correctly designed and constructed, provide interesting alternatives for the restoration of fish migration pathways in these regions.

scholarly journals Turning Pools in Stepped Fishways: Biological Assessment via Fish Response and CFD Models

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1186
Author(s):  
Francisco Javier Bravo-Córdoba ◽  
Juan Francisco Fuentes-Pérez ◽  
Jorge Valbuena-Castro ◽  
Andrés Martínez de Azagra-Paredes ◽  
Francisco Javier Sanz-Ronda
Keyword(s):  
3D Models ◽  
Fish Passage ◽  
Biological Assessment ◽  
Fish Migration ◽  
Longitudinal Development ◽  
Passive Integrated Transponder ◽  
Design Component ◽  
Cfd Models ◽  
Vertical Slot ◽  
Fish Response

With the aim of building more compact fishways and adapting them to field conditions to improve their location by fish, it is common to use turning pools, reducing the longitudinal development of the construction. However, depending on their design, turning pools may affect the hydraulic performance of the fishway and consequently the fish passage. To study these phenomena, turning pools in a vertical slot and in different configurations of submerged notches with bottom orifice fishway types were assessed. Both types of fishways were studied using numerical 3D models via OpenFOAM, a computational fluid dynamics software, in combination with fish responses, assessed with PIT (Passive Integrated Transponder) tag telemetry for three different species of potamodromous cyprinids in several fishways. Results show differences between the hydrodynamics of straight and turning pools, with lower values in the hydrodynamic variables in turning pools. Regarding fish behavior, the ascent was slower in turning pools but with no effect on passage success and without being a problem for fish migration. This information validates the use of turning pools as a key design component for fishways for studied species.

Analysis of fishways in the Middle and Lower Jinsha River Basin (China)

2021 ◽  
Author(s):  
Siqi Tong ◽  
Silke Wieprecht ◽  
Martin Schletterer
Keyword(s):  
River Basin ◽  
Jinsha River ◽  
Vertical Slot ◽  
Upper Yangtze River ◽  
Artificial Breeding ◽  
Longitudinal Connectivity ◽  
Target Fish ◽  
Regional Sustainable Development ◽  
Vertical Slot Fishway ◽  
Hydropower Stations

<p>This study was carried out in the middle and lower reaches of the Jinsha River in southwest China, which represents the upper Yangtze River. Hydraulic structures (14 cascade hydropower stations) are planned and/or constructed in this system, which is considered as largest hydropower base. We aim to summarize appropriate measures to restore the riverine continuum in the middle and lower reaches of the Jinsha River, where high-head cascade hydropower dams are located or planned.</p><p>We distributed a questionnaire to Chinese researchers in the related fields (scientists, hydropower operators and NGOs in China, n = 60). According to the responses, fishways, fish lift, fish lock, trap-and-truck system as well as fish hatcheries (artificial breeding) are recognized to ensure passing respectively preserving fish in the Jinsha River basin.</p><p>A longitudinal connectivity assessment of the study area revealed a severely disturbed continuity status. Based on the biological analyses of the demands of the target fish species and review of fish pass technologies, a vertical-slot fishway is proposed.</p><p>Considering the dam heights and the geographical conditions, it is recommended to combine the vertical-slot fishway with these alternatives to achieve a higher efficiency in passing fish as well as to recover the river continuity towards regional sustainable development.</p>

ADAPTIVE DATA DISSEMINATION IN MOBILE SENSOR NETWORKS

2009 ◽  
Vol 10 (04) ◽  
pp. 435-457
Author(s):  
ATHANASIOS KINALIS ◽  
SOTIRIS NIKOLETSEAS
Keyword(s):  
Sensor Networks ◽  
Data Dissemination ◽  
High Mobility ◽  
Cost Effective ◽  
Sensor Nodes ◽  
Inhibition Mechanism ◽  
Delivery Ratio ◽  
Message Delivery ◽  
Network Parameter ◽  
Trade Offs

Motivated by emerging applications, we consider sensor networks where the sensors themselves (not just the sinks) are mobile. Furthermore, we focus on mobility scenarios characterized by heterogeneous, highly changing mobility roles in the network. To capture these high dynamics of diverse sensory motion we propose a novel network parameter, the mobility level, which, although simple and local, quite accurately takes into account both the spatial and speed characteristics of motion. We then propose adaptive data dissemination protocols that use the mobility level estimation to optimize performance, by basically exploiting high mobility (redundant message ferrying) as a cost-effective replacement of flooding, e.g. the sensors tend to dynamically propagate less data in the presence of high mobility, while nodes of high mobility are favored for moving data around. These dissemination schemes are enhanced by a distance-sensitive probabilistic message flooding inhibition mechanism that further reduces communication cost, especially for fast nodes of high mobility level, and as distance to data destination decreases. Our simulation findings demonstrate significant performance gains of our protocols compared to non-adaptive protocols, i.e. adaptation increases the success rate and reduces latency (even by 15%) while at the same time significantly reducing energy dissipation (in most cases by even 40%). Also, our adaptive schemes achieve significantly higher message delivery ratio and satisfactory energy-latency trade-offs when compared to flooding when sensor nodes have limited message queues.

Analysis and Optimization of a Passive Micromixer With Curved-Shaped Baffles for Efficient Mixing With Low Pressure Loss in Continuous Flow

2010 ◽  
Author(s):  
Cesar A. Cortes-Quiroz ◽  
Alireza Azarbadegan ◽  
Emadaldin Moeendarbary ◽  
Mehrdad Zangeneh
Keyword(s):  
Pressure Loss ◽  
Cost Effective ◽  
Optimization Method ◽  
Secondary Flows ◽  
Design Parameters ◽  
Mixing Efficiency ◽  
Outlet Section ◽  
Optimization Strategy ◽  
Mixing Index ◽  
Trade Offs

Numerical simulations and an optimization method are used to study the design of a planar T-micromixer with curved-shaped baffles in the mixing channel. The mixing efficiency and the pressure loss in the mixing channel have been evaluated for Reynolds number (Re) in the mixing channel in the range 1 to 250. A Mixing index (Mi) has been defined to quantify the mixing efficiency. Three geometric dimensions: radius of baffle, baffles pitch and height of the channel, are taken as design parameters, whereas the mixing index at the outlet section and the pressure loss in the mixing channel are the performance parameters used to optimize the micromixer geometry. To investigate the effect of design and operation parameters on the device performance, a systematic design and optimization methodology is applied, which combines Computational Fluid Dynamics (CFD) with an optimization strategy that integrates Design of Experiments (DOE), Surrogate modeling (SM) and Multi-Objective Genetic Algorithm (MOGA) techniques. The Pareto front of designs with the optimum trade-offs of mixing index and pressure loss is obtained for different values of Re. The micromixer can enhance mixing using the mechanisms of diffusion (lower Re) and convection (higher Re) to achieve values over 90%, in particular for Re in the order of 100 that has been found the cost-effective level for volume flow. This study applies a systematic procedure for evaluation and optimization of a planar T-mixer with baffles in the channel that promote transversal 3-D flow as well as recirculation secondary flows that enhance mixing.

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