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Fish guidance structures with narrow bar spacing

2021-05-10T09:53:09Z

Ismailalbayrak:

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been enhanced in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Introduction=
[[file:IBR_schematic.png|thumb|250px|Figure 1: Longitudinal view of an inclined bar rack.]]
[[file:NBS_types.jpg|thumb|250px||Figure 2: Type of fish guidance structures with narrow bar spacing: angled bar rack with vertical bars (top), vertical streamwise bars (middle), horizontal bars (bottom).]]
[[file:HBR_schiffmühle.png|thumb|250px|Figure 3: The horizontal bar rack bypass system at the residual flow HPP Schiffmühle, Switzerland, during revision work in July 2018.]]
[[file:HBR_BS_sketch.png|thumb|250px|Figure 4: Principle sketch of an HBR-BS.]]
[[file:HBR_params.png|thumb|250px|Figure 5: Side view of an HBR illustrating different rack parameters; ho: approach flow depth, hds: downstream flow depth, Uo: mean upstream approach flow velocity from continuity, Uds: mean downstream flow velocity, hBo: bottom overlay height, hTo: top overlay height, sb: clear bar spacing, tb: bar thickness at thickest point, db: bar depth.]]
[[file:IBR_las_rives.png|thumb|250px|Figure 6: Construction and installation of the inclined trash racks of the HPP of Las Rives (France).]]

Different measures are used to protect downstream moving fish (details in [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.1) at hydropower plants and water intakes, of which two different fish guidance structures (FGSs) with narrow bar spacing were investigated within the FIThydro project: (I) inclined bar racks and (II) horizontal bar racks.

===Inclined bar racks===
Vertically Inclined Bar Racks (VIBR) consist of plane screens composed of elongated flat bars positioned in vertical planes aligned with the flow (Figure 1). The plane screen is inclined with an angle β with respect to the river bed in order to guide fish towards one or several surface bypasses located at the top of the rack (Raynal et al., 2013a). Another configuration consists of a perforated plate, which is called Vertically Inclined Perforated Plate (VIPP). Detailed information on the design and efficiency of both VIBR and VIPP is given in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverable] 3.4 and Lemkecher (2020).

===Angled bar racks===
Angled bar racks are installed at an angle α to the flow direction in plan view to guide fish towards a bypass located at the downstream end of the rack. Three types of angled racks with narrow bar spacing can be distinguished (Figures 2, 3 and 4):
*Classical” angled bar rack, with vertical bars angled with γ = 90°- α (cf Figure 2, (Raynal et al, 2013b)
*Angled bar rack with vertical bars oriented in the streamwise direction (γ = 0°) (cf. Figure 2) (Raynal et al., 2014).
*Horizontal Bar Rack - Bypass System (HBR)’ (Figures 2, 3 & 4) ([https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4, 2020; Albayrak et al., 2019; Lemkecher et al., 2020b; Meister, 2020; Meister et al., 2020a, b).

These rack structures are designed as physical fish exclusion and guidance barriers and may act as behavioral barriers depending on the bar spacing and fish size. The lower the bar spacing, the higher the fish will be reluctant to go through the rack. As a rule of thumb, the rack constitutes a physical barrier when the bar spacing is lower than 1/10 of the total length for most species including salmonids, but except for eels, which require bar spacing lower than 3% of their length (Ebel, 2016).

Figure 3 shows the horizontal bar rack – bypass system (HBR-BS) of the FIThydro case study residual HPP [[Schiffmühle test case|Schiffmühle]] at Limmat River, Switzerland, during revision work in 2018. The design discharge of the HPP is Qd = 14 m3/s and the HBR-BS was built in 2013 with foil-shaped bars, a clear bar spacing of sb = 20 mm, and a pipe bypass.

===Description of VIBRs and HBRs===

Vertically inclined bar racks (VIBR) and horizontal bar racks (HBRs) are physical barriers which prevent fish from entering the turbines at run-of-river HPPs. VIBRs and HBRs are characterized by narrow bar spacings ranging between 10 and 30 mm, such that they are physically impermeable for majority large share of the fish population (Figures 2 and 3; Meister et al., 2020). Bottom and top overlays can be used to enhance the guidance efficiency of sediments, floating debris, and bottom and surface oriented fish (Figure 4). An automated rack cleaning machine is needed to prevent the rack from clogging. Figure 4 illustrates that the bypass discharge is usually controlled with a restrictor and a ramp.

The bars of VIBRs and HBRs can be built with different bar shapes, such as rectangular, rectangular with a circular tip, rectangular with an ellipsoidal tip & tail, and foil-shaped (Figure 5). Most modern HBRs are equipped with foil-shaped bars or rectangular bars with an ellipsoidal tip & tail because of the reduced head losses (Meister et al., 2020a, Lemkecher et al. 2020a). Additionally, these bars can be cleaned easier than rectangular bars due to the thickness reduction from tip to tail (Meister et al., 2018). Figure 5 shows the different rack parameters of an HBR, including the clear bar spacing sb, the bar thickness tb, and the bar depth db (see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 3.4 for more information on HBR-BS)

=[[Methods, tools, and devices]]=

==During planning==
To prevent fish from passing through the FGS with narrow bar spacing, there are three design criteria: the bar spacing, the normal velocity (Vn; velocity component normal to the rack axis), which is directly linked to the rack surface, and the ratio of the rack parallel velocity (Vp) to the rack normal velocity, which should be higher than 1, i.e. Vp/Vn >1. The maximum values of the first two parameters depend on the species taken into account.
The recommended bar spacing and normal velocity (Vn ) are the same for inclined racks (VIBR), angled racks with horizontal bars (HBR) and with vertical streamwise bars, as the “louver effect” is not considered strong enough in such configuration.
For salmonid smolts, the bar spacing (for inclined and angled bar racks) has to be smaller than 10-15 mm to constitute a physical barrier (1/10 of body width). As eels do not show strong behavioural repulsion and are therefore likely to pass through the racks, it appeared necessary to implement physical barriers. In France, the recommended bar spacing (for inclined and angled bar racks) is generally 20 mm to stop female eels longer than 50-60 cm. The bar spacing can be reduced to 15 mm in case of a significant presence of males upstream of the HPP (Courret, et al., 2008).

For HBRs, the horizontal approach flow angle α, is selected such that the velocity component normal to the rack Vn does not exceed the sustained swimming speed of the target fish species. Approach flow velocities, typically varying between Uo = 0.40 and 0.80 m/s, lead to α = 20÷40°. The rack angle is therefore a compromise between limiting Vn on the one hand and the rack length on the other hand. For Vertically Inclined Bar Racks (VIBRs), rack inclinations of the order of 25° are favourable to fish guidance – thus confirming existing recommendations - and helping to limit the head losses (Courret and Larinier, 2008; Courret et al., 2015).
The head losses induced by HBRs can be predicted with the equations published in Meister et al. (2020a). These equations do not only take rack parameters, as defined in Figure 5, into account, but also different approach flow configurations as determined by the HPP layout such as diversion HPP or block-type HPP. If an HBR is installed in the headrace channel of a diversion HPP, the velocities are typically nearly equally distributed, which means that the criterion of Vp/Vn > 1 is fulfilled for HBRs with α < 45° (Meister et al., 2020b). If an HBR is installed at a block-type HPP, the streamline pattern is usually complex and Vp/Vn along the rack decreases towards the downstream rack end (Meister et al., 2020b). Likewise, Vn will be underestimated at the downstream rack end if the velocity components are calculated from continuity, which could lead to fish impingements. It is therefore recommended to determine the optimal HBR position with a numerical simulation such as described in Feigenwinter et al. (2019).

The head losses of VIBRs and VIPP can be predicted using the equations developed by Lemkecher (2020).
In addition to the design of a FGS with narrow bar spacing, the bypass design is important to safely collect and transport the fish and to return them unharmed to the river downstream of an HPP. Different bypass designs are described in literature such as the full depth open channel bypass, a bypass with a bottom and top opening, and a pipe bypass. The latter is not recommended because it can clog easily and fish avoid large velocity gradients at the inlet of the pipe bypass (Beck et al., 2020). Design of the bypass for VIBR and VIPP is described in the [https://www.fithydro.eu/deliverables-tech/ FIThydro Deliverables] 2.2 and 3.4.

The height and the width of the turbine intake influences the choice of the solution (inclined or angled). In addition, the possible location of the bypasses could modify the final solution. To reduce head losses, a particular attention has to be paid on the bar shape, the spacers and the support of the bar rack. For more details, please see the [https://www.fithydro.eu/deliverables-tech/FIThydro FIThydro Deliverables] 2.2 and 3.4; and [[Fish guidance structures with wide bar spacing]].

==During implementation==
The installation of fish guidance racks requires heavy lifting equipment and both the fixing and the placing of the structure requires a shut-down of the hydropower plant and the dewatering of the headrace channel or water intake (Figure 6). Installation of racks and a bypass system requires a suite of skilled labor on civil works.
==During operation==
After the installation of a FGS with narrow or wide bar spacing, the velocity field should be measured (e.g. with an [[Acoustic Doppler current profiler (ADCP)]]) in front of the FGS, at the bypass inlet, and in the bypass for different load cases. In parallel, a fish monitoring campaign, using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] is recommended to assess the fish protection and guidance efficiency of the FGS (FIThydro Deliverable 2.2). Efficiencies between 80% and 100% for eels and smolts are considered satisfactory. This can reduce the global mortality at a HPP to values of about 1-2% or even less, taking into account the movements via the spillway and survival rates when passing through the turbines (Tomanova, et al., 2018). The results of the monitoring campaign can be used to optimize the operation of the FGS, especially the operation of the bypass.

Reducing the bar spacing of the rack increases its blockage ratio and thus head losses. In addition, the rack is more quickly clogged by trash and organic fine material and hence cleaning during seasons of high floating debris transport poses a challenge. It is particularly crucial to avoid a permanent clogging by debris, which cannot be removed by the cleaning machine. Therefore, the hydraulic head losses of a FGS should be continuously measured and compared to the predictions calculated prior to construction. The head loss measurements should be also used to determine the flushing intervals of the bypass. That is, if a certain threshold value of the head losses is exceeded, the rack cleaning machine should start its operation automatically, and the bypass is opened to flush sediments and floating debris.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with narrow bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with narrow bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="vertical-align:bottom;"
|- style="font-weight:bold;"
! style="font-weight:normal;" |
! Vertically inclined bar rack (VIBR/VIPP)
! Angled vertical bar rack (AVBR)
! Angled vertical streamwise bar rack (AVSBR)
! Angled horizontal bar rack (HBR)
|-
| style="font-weight:bold;" | Fish species
| Tested on: smolt, European eel
| Tested on: smolt, European eel
| N/A
| All
|-
| style="font-weight:bold;" | Power losses
| Low head loss and symmetrical turbine admission flow
| High head loss and mild assymetric turbine admission flow
| Low head loss and symmetrical turbine admission flow
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold;" | Certainty of effect
| Very certain
| Very certain
| Moderately certain
| Very certain
|- style="text-align:center;"
| style="font-weight:bold; text-align:left;" | TRL
| 9
| 9
| 4
| 9
|}

{{Fish guidance structures with narrow bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I.; Maager, F.; Boes, R.M. (2019). An experimental investigation on fish guidance structures with horizontal bars. Journal of Hydraulic Research, 58(3): 516-530.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://vaw.ethz.ch/en/the-institute/publications/vaw-communications/2010-2019.html
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier M. (2008). Guide pour la conception de prises d’eau “ichtyo-compatibles” pour les petites centrales hydroélectriques [Guide for the design of fish-friendly intakes for small hydropower plants]. France: Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME). Report No: RAPPORT GHAAPPE RA.08.04. http://www.onema.fr/IMG/pdf/2008_027.pdf (in French).
* Courret, D., Larinier, M., David, L., Chatellier, L. (2015). Development of criteria for the design and dimensioning of fish-friendly intakes for small hydropower plant. Fish Passage 2015, Groningen, June 22-24.
* Ebel, G. (2016). Fish Protection and Downstream Passage at Hydro Power Stations — Handbook of Bar Rack and Bypass Systems. Bioengineering Principles, Modelling and Prediction, Dimensioning and Design. ISBN 9783000396861. 2nd edn. Büro für Gewässerökologie und Fischereibiologie Dr. Ebel, Halle (Saale), Germany [in German].
* Feigenwinter, L.; Vetsch, D.F.; Kammerer, S.; Kriewitz, C.R.; Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and expert knowledge. Sustainability, 11(6), 1646. https://www.doi.org/10.3390/su11061646
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Lemkecher, F., Chatellier, L., Courret, D., David, L., (2020a). Experimental study of fish-friendly angled trash racks with horizontal bars. Journal of Hydraulic Research (in revision)
* Lemkecher F. ; Chatellier L. ; Courret D. ; David L., (2020b). Contribution of different elements of inclined trash racks to head losses modelling. Water, 12(966). https://doi.org/10.3390/w12040966
* Lemkecher F. (2020). Étude des grilles des prises d’eau ichtyocompatibles. Thesis of University of Poitiers, France.
* Meister, J.; Fuchs, H.; Boes, R.M. (2018). Hydraulische Laboruntersuchungen horizontaler Fischleitrechen (‘Hydraulic laboratory investigations of horizontal fish guidance racks’). zekHydro, 15(2): 54–56. http://dx.doi.org/10.3929/ethz-b-000295001[in German].
* Meister, J. (2020). Fish protection and guidance at water intakes with horizontal bar rack bypass systems. VAW-Mitteilung 258 (R.M. Boes, ed.). Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Switzerland. https://ethz.ch/content/dam/ethz/special-interest/baug/vaw/vaw-dam/documents/das-institut/mitteilungen/2020-2029/258.pdf
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020a). Head Losses of Horizontal Bar Racks as Fish Guidance Structures. Water, 12(2): 475. http://dx.doi.org/10.3390/w12020475.
* Meister, J.; Fuchs, H.; Beck, C.; Albayrak, I.; Boes, R.M. (2020b). Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures. Water, 12(1): 280. http://dx.doi.org/10.3390/w12010280.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., & Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014): Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* Tomanova, S. et al. (2018). Protecting Efficiently Sea-migrating Salmon Smolts from Entering Hydropower Plant Turbines with Inclined or Oriented Low Bar Spacing Racks . Ecological Engineering 122, p. 143-152. DOI : 10.1016/j.ecoleng.2018.07.034.
* Turnpenny, A.W.H.; O’Keeffe, N (2005). Screening for Intake and Outfalls: a best practice guide. Technical Report SC030231, Environment Agency, Bristol, United Kingdom.

[[category:Downstream fish migration measures]][[category:Solutions]][[Category:Enhanced in FIThydro]]

Fish guidance structures with wide bar spacing

2021-05-10T09:52:24Z

Ismailalbayrak:

[[file:icon_downstream.png|right|150px|link=[[Downstream fish migration]]]]
{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}
=Introduction=
[[file:FGS_layouts.jpg|thumb|250px|Figure 1: Different FGS layouts (a) Louver, (b) Angled Bar Rack (ABR), (c) Modified angled Bar Rack (MBR) and Curved-Bar Racks (CBRs) with upstream tip angle of (d) 90° and (e) 45°]]
[[file:CBR_schematic.jpg|thumb|250px|Figure 1: Top view of a schematic CBR arrangement with indicated rack angle α, power canal and bypass. The fish are guided along the rack towards the bypass, where they pass downstream]]

The revised Swiss Waters Protection Act (WPA) of 2011 demands the restoration of water bodies and the elimination of negative impacts of hydropower plants (HPPs) regarding fish migration until 2030. Similar demands are stated by the European Water Framework Directive (WFD) of 2000.

To minimize fish injuries or mortality during turbine passage at Run-of-River (RoR) HPPs and thus to fulfill the demands of the WPA and WFD, mechanical behavioural Fish Guidance Structures (FGS) with wide bar spacing and vertical bars have been developed for using at RoR HPPs and water intakes with high design discharges. These are Louvers, Angled Bar Racks (ABR), Modified angled Bar Racks (MBR) and Curved-Bar Racks (CBR) (Figure 1, Bates and Vinsonhaler, 1957; Raynal et al., 2013a; Albayrak et al., 2018 & 2020; Beck et al., 2020a &b). The CBRs have been developed in FIThydro (Figure 1d, e and 2).

All four FGSs feature wide clear bar spacing ≥ 25 mm and are classified as mechanical behavioural fish protection barriers (Fig. 1). Depending on fish size and bar spacing, they may partly function as physical barriers, i.e. preventing fish with minimum body dimensions greater than the clear bar spacing from passage. Louvers are made of vertical straight bars placed at an angle β = 90° to the flow direction mounted in a rack (Fig. 1a). The rack is placed across an intake canal at an angle to the flow direction of typically α= 15° to 30°. Classical ABRs function similar to louvers but their bars are placed at 90° to the rack axis, so that β varies with the main angle α, i.e. β = 90°− α (Fig. 1b), whereas MBRs have an independent variation of α and β with β ≠ 90°−α (Fig. 1c; Raynal et al., 2014; Albayrak et al., 2018 & 2020,). The CBRs consist of a series of vertical curved-bars instead of straight bars. The plan view angle between the upstream bar tip and the flow direction ranges from β = 45° to 90°, while the angle at the downstream end of the bar is optimally δ = 0°, i.e. parallel to the flow direction in the power canal (Fig. 1d, e and 2). All these four FGS types with clear bar spacings of s ≥ 25 mm guide fish to a bypass with hydrodynamic cues created by the bars instead of physically blocking fish from a water intake. When approaching the structure, fish should be able to perceive the elevated pressure and velocity gradients around and between the bars, resulting in avoidance behaviours. The velocity component parallel to the rack Vp, guides the fish towards the bypass. Effective guidance of such FGSs depends also on maintaining the ratio between Vp and rack normal velocity Vn above 1, i.e. Vp / Vn > 1 upstream of the bypass (Courret & Larinier, 2008). Furthermore, to ensure that fish can swim actively along the FGS without exhaustion, the rack normal velocity should be smaller than the sustained swimming speed of fish, i.e. Vn < Vsustained. A general value of Vsustained= 0.50 m/s is recommended for smolts and silver eels (Raynal et al., 2013b) as a first proxy. In general, the value of Vsustained = 0.50 m/s is recommended for the design of a FGS, if the fish fauna is not specified; else, Vsustained should be target fish specific. USBR (2006) recommends the ratio of mean bypass velocity Uby,in to the mean approach flow velocity Uo, between1.1 and 1.5 for louvers.

Detailed information and case study performance evaluation of louver systems are presented in USBR (2006). In addition, Albayrak et al. (2018, 2020) investigated the hydraulics and fish protection and guidance efficiencies of Louvers and MBRs in the laboratory. Albayrak et al. (2018) developed a headloss prediction equation for Louver, ABR and MBR. Furthermore, Albayrak et al. (2020) reported the flow fields and fish guidance efficiencies of a Louver with α = 15° and s = 50 mm and MBR configurations with α = 15° and 30°, s = 50 mm and with and without bottom overlays tested with barbel, spirlin, European grayling, European eel and brown trout. The results show that MBRs with α = 15° with and without overlay successfully guided 90% and 80% of the tested fish species, respectively. Furthermore, MBRs with α = 30° with an overlay guided 95% of the fish. Compared to Louvers and ABRs, MBRs reduce the head losses by ~5 times and ~2, respectively (see Table 1). Despite low head losses for MBRs, losses are still relatively high compared to conventional trash racks and the downstream flow field is still asymmetrical, which may negatively affect turbine efficiency.

Due to the flow straightening effect, the new CBR results in ~20 and ~4 folds lower head losses compared to the same Louver and MBR configurations (Table 1) and in quasi-symmetrical downstream flow (Beck, 2020 & Beck et al., 2020b), improving the rack downstream flow field and possibly HPP turbine efficiency. Furthermore, systematic ethohydraulic tests for a hydraulically optimized CBR configuration with β = 45° and s = 50 mm show fish protection and guidance efficiencies above 75% for spirlin, barbel, nase and salmon parr . The efficiency of the laboratory tests were below 75% for brown trout and eel (Beck, 2019 and 2020).
Given the significantly reduced head losses and high fish guidance and protection efficiencies, CBRs developed in FIThydro present a high potential over Louvers, ABRs and MBRs with straight bars for a safe downstream fish migration at hydropower plants at minimum negative economic impacts (for more on CBRs, see Beck, 2020 and FIThydro deliverable 3.4).

''Table 1: Comparison of head losses of FGSs with wide bar spacing for the rack configuration of α = 30°, s = 50 mm, d =100 mm, t = 10 mm (Fig.1).''
{| class="wikitable" style="text-align:center;"
|-
! style="text-align:left;" | FGS type
! Louver
! ABR
! MBR
! style="font-weight:bold;" | CBR
|-
| style="text-align:left;" | Bar angle, β
| 90°
| 60°
| 45°
| 45°
|-
| style="text-align:left;" | Head loss coefficient, ξ
| style="vertical-align:middle;" | 13.7
| style="vertical-align:middle;" | 5.0
| style="vertical-align:middle;" | 2.8
| style="vertical-align:middle;" | 0. 7
|}

=[[Methods, tools, and devices]]=

==During planning==
[[file:velocity_fields_bannwil.jpg|thumb|250px|Figure 1: Exemplary depth-averaged velocity fields [cm/s] upstream of HPP Bannwil measured with boat-mounted ADCP at a discharge of 402 m3/s ]][[file:numerical_modelling_bannwil.jpg|thumb|250px|Figure 1: Exemplary variant study for HPP Bannwil using numerical modelling. Normal (left) and tangential (right) flow velocities at potential FGS positions upstream of the turbine inlets for scenario 1a for FGS angled at 37°]]

To design a FGS with wide bar spacing and its corresponding bypass system (BS) at a given HPP, detailed site-specific information is needed. The information can be obtained from construction plans and measurements on site. It is recommended to (I) identify and utilize fish migration corridors using [[Radio telemetry|radio]] or [[Acoustic telemetry|acoustic]] telemetry technique; (II) consider behaviour and biomechanical properties of target fish species; and (III) match the hydraulic conditions of a FGS-BS to (I) and (II). In order to assess the hydraulics of a FGS-BS, velocity and bathymetry measurements using e.g. an [[Acoustic Doppler current profiler (ADCP)]] should be conducted (exemplary velocity data from the test case HPP Bannwil, Figure 3). Based on such data, a physical or numerical model of the HPP (Feigenwinter et al., 2019) can be constructed. With either model, positioning and geometric optimization of FGS-BS can be done (numerical model results for [[Bannwil test case|HPP Bannwil]], Figure 4, see [https://www.fithydro.eu/deliverables-tech/ FIThydro deliverable] 2.2). Finally, it is recommended to integrate the HPP’s operating conditions and the hydrological boundary conditions of the studied site.

The construction of a FGS-BS at an existing HPP will in most cases lead to a temporary interruption of the HPP operation and thus to production losses. The construction of the rack itself is comparable to the construction of a conventional HPP trash rack. An additional bridge carrying the rack cleaning machine, which in most cases is analogue to conventional machines used at classical intake trashracks (Beck, 2020), should be installed above the FGS-BS.

==During implementation==
Construction of fish guidance structures with wide bar opening requires heavy lifting equipment and both fixing and placing of the structure needs to be done when the hydropower plant is brought to full stop. Installation of racks, cleaning machine and a bypass system requires a suite of skilled labor on civil works.

==During operation==
Similar to the planning phase, after the construction of a FGS-BS at a HPP site, velocity measurements - using e.g. an [[Acoustic Doppler current profiler (ADCP)|ADCP]] - and fish monitoring using [[Radio telemetry|radio]]/[[Acoustic telemetry|acoustic]] telemetry or [[Radio frequency identification with passive integrated transponder (PIT tagging)|PIT-tagging]] are recommended to evaluate the effect of the FGS-BS on the flow field and its fish protection and guidance efficiencies. Based on the monitoring results, further optimization of the FGS-BS should be made, if needed.

=Relevant MTDs and test cases=
{{Suitable MTDs for Fish guidance structures with wide bar spacing}}

=Classification table=
This article describes several different types of fish guidance structures with wide bar spacing. The classification table does not represent all of them for every topic. Therefore, an additional table is added to highlight where and how the types differ.

{| class="wikitable" style="vertical-align:bottom;"
|- style="font-weight:bold; text-align:center;"
! style="font-weight:normal; text-align:left;" |
! Louvres and angled bar rack (ABR)
! Modified angled bar rack (MBR)
! Curved-bar rack (CBR)
|-
| style="font-weight:bold;" | Fish species
| All
| Tested on: barbel, spirlin, European grayling, European eel, brown trout
| Tested on: spirlin, barbel, brown trout, nase, European eel, salmon parr
|-
| style="font-weight:bold;" | Power losses
| Significant head losses and strong assymetric turbine admission flow (compared to MBR and CBR)
| High head loss and mild assymetric turbine admission flow (compared to CBR)
| Low head loss and quasi-symmetrical turbine admission flow
|-
| style="font-weight:bold;" | Certainty of effect
| Very uncertain
| Moderately certain
| Moderately certain
|- style="text-align:center;"
| style="font-weight:bold; text-align:left;" | TLR
| 9
| 4
| 4
|}
{{Fish guidance structures with wide bar spacing}}

=Relevant literature=
* Albayrak, I., Kriewitz, C.R., Hager, W.H., Boes, R.M. (2018). An experimental investigation on louvres and angled bar racks. Journal of Hydraulic Research, 56(1): 59-75, https://doi.org/10.1080/00221686.2017.1289265.
* Albayrak, I., Boes, R.M., Kriewitz-Byun, C.R., Peter, A., Tullis, B.P. (2020). Fish guidance structures: new head loss formula, hydraulics and fish guidance efficiencies. Journal of Ecohydraulics, https://doi.org/10.1080/24705357.2019.1677181.
* Bates, D.W., Vinsonhaler, R. (1957). Use of louvers for guiding fish. Trans. American Fish Soc. 86(1):38–57.
* Beck, C. (2019). Hydraulic and fish-biological performance of fish guidance structures with curved bars. In proc. 38th International Association for Hydro-Environmental Engineering and Research (IAHR) World Congress, Panama City, Panama, https://doi.org/10.3929/ethz-b-000371526.
* Beck, C. (2020). Fish protection and fish guidance at water intakes using innovative curved-bar rack bypass systems. VAW-Mitteilung 257 (R.M. Boes, ed). VAW, ETH Zurich, Switzerland. https://ethz.ch/content/dam/ethz/special-interest/baug/vaw/vaw-dam/documents/das-institut/mitteilungen/2020-2029/257.pdf
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020a). Hydraulic performance of fish guidance structures with curved bars: Part 1: Head loss assessment. Journal of Hydraulic Research,58(5): 807-818, https://doi.org/10.1080/00221686.2019.1671515.
* Beck, C., Albayrak, I., Meister, J., Boes R.M. (2020b). Hydraulic performance of fish guidance structures with curved bars: Part 2: Flow fields. Journal of Hydraulic Research, 58(5): 819-830, https://doi.org/10.1080/00221686.2019.1671516.
* Courret, D., Larinier, M. (2008). Guide pour la conception de prises d’eau ‘ichtyocompatibles’ pour les petites centrales hydroélectriques (Guide for the design of fish-friendly intakes for small hydropower plants). Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME) (in French).
* Feigenwinter, L., Vetsch, D.E., Kammerer, S., Kriewitz, C.R., Boes, R.M. (2019). Conceptual Approach for Positioning of Fish Guidance Structures Using CFD and Expert Knowledge. Sustainability, 11(6).
* FIThydro Deliverable 2.2 (2019). Working basis of solutions, models, tools and devices and identification of their application range on a regional and overall level to attain self-sustained fish populations. https://www.fithydro.eu/deliverables-tech/.
* FIThydro Deliverable 3.4 (2020). Enhancing and customizing technical solutions for fish migration. https://www.fithydro.eu/deliverables-tech/.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013a). An experimental study on fish-friendly trashracks - Part 2. Angled trashracks. Journal of Hydraulic Research, 51(1): 67-75.
* Raynal, S., Chatellier, L., Courret, D., Larinier, M., Laurent, D. (2013b). An experimental study on fish-friendly trashracks - Part 1. Inclined trashracks. Journal of Hydraulic Research, 51(1), 56-66.
* Raynal, S., Châtellier, L., Courret, D., Larinier, M., David, L. (2014). Streamwise bars in angled trashracks for fish protection at water intakes. Journal of Hydraulic Research, 52 (3), 426-431.
* USBR (2006). Fish protection at water diversions – A guide for planning and designing fish exclusion facilities. Technical Report. U.S. Department of the Interior, Bureau of Reclamation.

[[category:Downstream fish migration measures]][[category:Solutions]] [[Category:developed in FIThydro]]

Template:Fact box for Schiffmühle

2021-05-10T09:49:22Z

Ismailalbayrak:

{| class="wikitable" style="float:right;width:350px;"
! colspan="2" style="text-align: center;background-color:#2cb4da; color:#ffffff;" | Fact box: Schiffmühle
|-
| Country
| Switzerland
|-
| River
| Limmat
|-
| Operator
| Limmatkraftwerke AG
|-
| Capacity
| 0.5 MW
|-
| Head
| 2.97 m
|-
| Inter-annual discharge
| 14 m3/s
|-
| Turbine(s)
| 1 Bevel gear bulb turbine
|-
| Detailed report
|[[:file:Test case presentation Schiffmühle.pdf|Click for pdf]]
|}

File:Test case presentation Schiffmühle.pdf

2021-05-10T09:48:51Z

Ismailalbayrak:

Test case presentation Schiffmühle

Template:Fact box for Bannwil

2021-05-10T09:45:49Z

Ismailalbayrak:

{| class="wikitable" style="float:right;width:350px;"
! colspan="2" style="text-align: center;background-color:#2cb4da; color:#ffffff;" | Fact box: Bannwil
|-
| Country
| Switzerland
|-
| River
| Aare
|-
| Operator
| BKW Energie AG
|-
| Capacity
| 28.5 MW
|-
| Head
| 5.5 - 8.5 m
|-
| Inter-annual discharge
| 268 m3/s
|-
| Turbine(s)
| 3 Bulb turbines
|-
| Detailed report
|[[:file:Test case presentation Bannwil HPP.pdf|Click for pdf]]

File:Test case presentation Bannwil HPP.pdf

2021-05-10T09:44:22Z

Ismailalbayrak:

Test case presentation Bannwil HPP

File:3d fish tracking installation1.jpg

2020-10-02T15:56:45Z

Ismailalbayrak:

{{Information
|author= VAW, ETH Zurich
|source= VAW, ETH Zurich
|description= 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich
}}

File:3d fish tracking installation1.jpg

2020-10-02T15:56:25Z

Ismailalbayrak:

{{Information
|author= VAW, ETH Zurich
|source=
|description= 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich
}}

File:HPP Bannwil River Aare.jpg

2020-10-02T15:51:58Z

Ismailalbayrak:

{{Information
|author= Ismail Albayrak
|source= VAW, ETH Zurich
|description=Aerial view of the Bannwil powerplant/dam.
}}

Acoustic Doppler current profiler (ADCP)

2020-10-02T15:46:57Z

Ismailalbayrak:

=Quick summary=
[[file:adcp_example_units.png|thumb|250px|Figure 1: Examples of ADCPs: (a) Teledyne RiverPro with 5 beams (source: http://www.teledynemarine.com) and (b) Sontek M9 with 9 beams and S5 with 5 beams (source: https://www.sontek.com).]]
[[file:adcp_qboat.png|thumb|250px|Figure 2: Teledyne Marine Q-boat of VAW equipped with Riverpro ADCP and DGPS (source: VAW, ETH Zurich).]]
[[file:adcp_wse.png|thumb|250px|Figure 3: Water surface elevation along the power canal of HPP Schiffmühle (black line: DGPS data and red line: total station data) (source: VAW, ETH Zurich).]]
[[file:adcp_workflow.png|thumb|250px|Figure 4: Workflow used for post-processing of ADCP data (click to expand) (source: VAW, ETH Zurich)..]]
[[file:adcp_output.png|thumb|250px|Figure 5: Depth averaged flow velocities upstream of the HPP Bannwil measured with the ADCP boat at a discharge of 402 m3/s (background image: © 2018 swisstopo (JD 100041)) (source: VAW, ETH Zurich).]]

Developed by: Several Companies

Date: 2020

Type: [[:Category:Devices|Device]]

=Introduction=
Acoustic Doppler Current Profiler (ADCP) allows quick, easy and accurate measurements of 3D velocity time series and bathymetry, and computation of discharges in rivers, estuaries, lakes and reservoirs as well as oceans. ADCP data can be used for calibration of numerical models, hydraulic studies (for example, flow field around hydraulic structures), habitat quality assessment and modelling, hydro-morphologic surveys and sediment studies.

The ADCP is equipped with multi-beams (three up to nine beams, Figure 1), which emit acoustic energy at a known frequency and record the frequency of the acoustic energy backscattered by the particles in the water column. The velocity of the water flow along each beam is computed based on the change in the frequency of the emitted and backscattered acoustic energy, i.e. the Doppler shift. Detailed information on the ADCP working principle and its limitations are described by Simpson (2002). The ADCP beams are positioned to 20 or 30 degree away from the vertical axis. By using a simple trigonometry, 3D velocity components are computed from the Doppler shifts measured with three or four sonar beams. In the latter, a redundant, fourth beam is used to compute error
velocity, which is the difference between a velocity measured by one set of three beams and a velocity measured by another set of three beams at the same time (Simpson, 2002). The error velocity is used to evaluate the assumption of horizontal homogeneity. The frequency of the ultrasonic sound transmitted by commercially available ADCPs ranges from 30 kHz to 3000 KHz (Simpson, 2002). ADCP can be used at a fixed position, i.e. stationary, or mounted to a tethered boat, manned boat or a remote-controlled boat (Mueller et al., 2013). Non-stationary i.e. moving boat ADCP measurements yield the flow velocity and direction relative to the boat and hence the velocity of the boat should be accounted for by using either bottom tracking or global positioning system (GPS) to determine true flow velocity.

=Application=
Within the scope of FIThydro, high resolution 3D velocity, as well as bathymetry measurements, have been conducted using an ADCP mounted on a high speed remote-controlled boat at two hydropower plants (HPP) in Switzerland since the beginning of 2018. The models of the ADCP and the boat are River Pro 1200 kHz including piston style four-beam transducer with a 5th, independent 600 kHz vertical beam and Q-Boat purchased from Teledyne Marine, USA, respectively (Figure 2). An external Differential GPS (DGPS) system from A326 AtlasLink (Hemisphere) was used to accurately measure the positions of the ADCP. One set of the battery for the Q-boat allowed us to make measurements for 4 hours up to 10 hours depending on the flow velocity and field conditions i.e. temperature.

Compass calibration and moving bed tests are conducted before each ADCP measurement at the case study HPPs. The Test Case study HPP Schiffmühle is located on the 35 km long river Limmat between in Untersiggenthal and Turgi near Baden in Switzerland (see the Test Case presentation file for HPP Schiffmühle). Two transects of ADCP at each densely spaced cross-section along the river were enough but high accuracy of altitude data was required for the bathymetry measurements at the HPP and in general. The present DGPS system resulted in ±1m of errors in altitude measurements (Figure 3, black line). Therefore, use of a total station, which is time consuming, or real-time kinematic (RTK) GPS is recommended to accurately determine water surface and hence bathymetry (Figure 3, red line from total station measurements).

Furthermore, the test results from the HPP Bannwil located on River Aare in canton Bern indicated that averaging of at least 8 transects or even more at each cross-section is needed to obtain robust and smooth velocity field and accurate discharge data at highly turbulent and 3D flows occurring in rivers, turbine inlet and outlets or other hydraulic structures (see the Test Case presentation file for HPP Bannwil).

The ADCP data from both HPPs Schiffmühle and Bannwil are post-processed according to the workflow sketched in Figure 4 using the software WinRiver II (Teledyne software) and velocity mapping toolbox (VMT, Matlab based software for processing and visualizing ADCP data provided by U.S. Geological Survey). Figure 5 shows the depth-averaged velocities at the HPP Bannwil plotted with VMT. VMT can be used with the output files from Sontek ADCPs. For further data analysis and presentation on the maps like river bed changes, Q-GIS (free software) or ARC-GIS (Commercial software) are also recommended.

The present system based on the remote-controlled boat platform has advantages over the tethered boat ADCP application. These are less man-power needed, faster and more measurements in a shorter time, no flow disturbance and interference with beams and smoother movement of the boat.

=Relevant mitigation measures and test cases=
{{Suitable measures for Acoustic Doppler current profiler (ADCP)}}

=Other information=
The total costs for the Teledyne RiverPro 1200 kHz, Teledyne Q-boat and DGPS from Hemisphere Atlas link amount to approx. 22’000 €, 21’200 € and 3’340 € respectively. The costs of shipping, VAT, some mounting apparatus and long-range radio modem are excluded. For current costs of the equipment, we recommend to ask the corresponding supplier. Note that Q-boat can also house Sontek RiverSurveyor M9. Furthermore, a rugged laptop for field use is recommended.

=Relevant literature=
*Mueller, D.S., Wagner, C.R., Rehmel, M.S., Oberg, K.A., Rainville, F. (2013). Measuring discharge with acoustic Doppler current profilers from a moving boat (ver. 2.0, December 2013), U.S. Geological Survey Techniques and Methods, book 3, chap. http://dx.doi.org/10.3133/tm3A22.

*Simpson, M.R. (2002). Discharge measurements using a broadband acoustic Doppler current profiler. Open-file Report 2001-1, https://doi.org/10.3133/ofr011.

Links to the suppliers of equipment:

*Teledyne Marine, ADCP RiverPro: http://www.teledynemarine.com/riverpro-adcp?ProductLineID=13

*Teledyne Marine, Q-Boat: http://www.teledynemarine.com/Lists/Downloads/Q-Boat_1800_Datasheet.pdf

*Hemisphere Atlas DPS: https://hemispheregnss.com/Atlas/atlaslinke284a2-gnss-smart-antenna-1226

*Sontek ADCP M9: https://www.sontek.com/riversurveyor-s5-m9

Software for ADCP data analysis:

*Velocity Mapping Toolbox: https://hydroacoustics.usgs.gov/movingboat/VMT/VMT.shtml

*Q-GIS: https://qgis.org/en/site/

*ARC-GIS: https://www.esri.com/en-us/arcgis/about-arcgis/overview

=Contact information=

[[Category:Devices]]

Acoustic Doppler current profiler (ADCP)

2020-10-02T15:46:35Z

Ismailalbayrak:

=Quick summary=
[[file:adcp_example_units.png|thumb|250px|Figure 1: Examples of ADCPs: (a) Teledyne RiverPro with 5 beams (source: http://www.teledynemarine.com) and (b) Sontek M9 with 9 beams and S5 with 5 beams (source: https://www.sontek.com).]]
[[file:adcp_qboat.png|thumb|250px|Figure 2: Teledyne Marine Q-boat of VAW equipped with Riverpro ADCP and DGPS (source: VAW, ETH Zurich).]]
[[file:adcp_wse.png|thumb|250px|Figure 3: Water surface elevation along the power canal of HPP Schiffmühle (black line: DGPS data and red line: total station data).]]
[[file:adcp_workflow.png|thumb|250px|Figure 4: Workflow used for post-processing of ADCP data (click to expand) (source: VAW, ETH Zurich)..]]
[[file:adcp_output.png|thumb|250px|Figure 5: Depth averaged flow velocities upstream of the HPP Bannwil measured with the ADCP boat at a discharge of 402 m3/s (background image: © 2018 swisstopo (JD 100041)) (source: VAW, ETH Zurich)..]]

Developed by: Several Companies

Date: 2020

Type: [[:Category:Devices|Device]]

=Introduction=
Acoustic Doppler Current Profiler (ADCP) allows quick, easy and accurate measurements of 3D velocity time series and bathymetry, and computation of discharges in rivers, estuaries, lakes and reservoirs as well as oceans. ADCP data can be used for calibration of numerical models, hydraulic studies (for example, flow field around hydraulic structures), habitat quality assessment and modelling, hydro-morphologic surveys and sediment studies.

The ADCP is equipped with multi-beams (three up to nine beams, Figure 1), which emit acoustic energy at a known frequency and record the frequency of the acoustic energy backscattered by the particles in the water column. The velocity of the water flow along each beam is computed based on the change in the frequency of the emitted and backscattered acoustic energy, i.e. the Doppler shift. Detailed information on the ADCP working principle and its limitations are described by Simpson (2002). The ADCP beams are positioned to 20 or 30 degree away from the vertical axis. By using a simple trigonometry, 3D velocity components are computed from the Doppler shifts measured with three or four sonar beams. In the latter, a redundant, fourth beam is used to compute error
velocity, which is the difference between a velocity measured by one set of three beams and a velocity measured by another set of three beams at the same time (Simpson, 2002). The error velocity is used to evaluate the assumption of horizontal homogeneity. The frequency of the ultrasonic sound transmitted by commercially available ADCPs ranges from 30 kHz to 3000 KHz (Simpson, 2002). ADCP can be used at a fixed position, i.e. stationary, or mounted to a tethered boat, manned boat or a remote-controlled boat (Mueller et al., 2013). Non-stationary i.e. moving boat ADCP measurements yield the flow velocity and direction relative to the boat and hence the velocity of the boat should be accounted for by using either bottom tracking or global positioning system (GPS) to determine true flow velocity.

=Application=
Within the scope of FIThydro, high resolution 3D velocity, as well as bathymetry measurements, have been conducted using an ADCP mounted on a high speed remote-controlled boat at two hydropower plants (HPP) in Switzerland since the beginning of 2018. The models of the ADCP and the boat are River Pro 1200 kHz including piston style four-beam transducer with a 5th, independent 600 kHz vertical beam and Q-Boat purchased from Teledyne Marine, USA, respectively (Figure 2). An external Differential GPS (DGPS) system from A326 AtlasLink (Hemisphere) was used to accurately measure the positions of the ADCP. One set of the battery for the Q-boat allowed us to make measurements for 4 hours up to 10 hours depending on the flow velocity and field conditions i.e. temperature.

Compass calibration and moving bed tests are conducted before each ADCP measurement at the case study HPPs. The Test Case study HPP Schiffmühle is located on the 35 km long river Limmat between in Untersiggenthal and Turgi near Baden in Switzerland (see the Test Case presentation file for HPP Schiffmühle). Two transects of ADCP at each densely spaced cross-section along the river were enough but high accuracy of altitude data was required for the bathymetry measurements at the HPP and in general. The present DGPS system resulted in ±1m of errors in altitude measurements (Figure 3, black line). Therefore, use of a total station, which is time consuming, or real-time kinematic (RTK) GPS is recommended to accurately determine water surface and hence bathymetry (Figure 3, red line from total station measurements).

Furthermore, the test results from the HPP Bannwil located on River Aare in canton Bern indicated that averaging of at least 8 transects or even more at each cross-section is needed to obtain robust and smooth velocity field and accurate discharge data at highly turbulent and 3D flows occurring in rivers, turbine inlet and outlets or other hydraulic structures (see the Test Case presentation file for HPP Bannwil).

The ADCP data from both HPPs Schiffmühle and Bannwil are post-processed according to the workflow sketched in Figure 4 using the software WinRiver II (Teledyne software) and velocity mapping toolbox (VMT, Matlab based software for processing and visualizing ADCP data provided by U.S. Geological Survey). Figure 5 shows the depth-averaged velocities at the HPP Bannwil plotted with VMT. VMT can be used with the output files from Sontek ADCPs. For further data analysis and presentation on the maps like river bed changes, Q-GIS (free software) or ARC-GIS (Commercial software) are also recommended.

The present system based on the remote-controlled boat platform has advantages over the tethered boat ADCP application. These are less man-power needed, faster and more measurements in a shorter time, no flow disturbance and interference with beams and smoother movement of the boat.

=Relevant mitigation measures and test cases=
{{Suitable measures for Acoustic Doppler current profiler (ADCP)}}

=Other information=
The total costs for the Teledyne RiverPro 1200 kHz, Teledyne Q-boat and DGPS from Hemisphere Atlas link amount to approx. 22’000 €, 21’200 € and 3’340 € respectively. The costs of shipping, VAT, some mounting apparatus and long-range radio modem are excluded. For current costs of the equipment, we recommend to ask the corresponding supplier. Note that Q-boat can also house Sontek RiverSurveyor M9. Furthermore, a rugged laptop for field use is recommended.

=Relevant literature=
*Mueller, D.S., Wagner, C.R., Rehmel, M.S., Oberg, K.A., Rainville, F. (2013). Measuring discharge with acoustic Doppler current profilers from a moving boat (ver. 2.0, December 2013), U.S. Geological Survey Techniques and Methods, book 3, chap. http://dx.doi.org/10.3133/tm3A22.

*Simpson, M.R. (2002). Discharge measurements using a broadband acoustic Doppler current profiler. Open-file Report 2001-1, https://doi.org/10.3133/ofr011.

Links to the suppliers of equipment:

*Teledyne Marine, ADCP RiverPro: http://www.teledynemarine.com/riverpro-adcp?ProductLineID=13

*Teledyne Marine, Q-Boat: http://www.teledynemarine.com/Lists/Downloads/Q-Boat_1800_Datasheet.pdf

*Hemisphere Atlas DPS: https://hemispheregnss.com/Atlas/atlaslinke284a2-gnss-smart-antenna-1226

*Sontek ADCP M9: https://www.sontek.com/riversurveyor-s5-m9

Software for ADCP data analysis:

*Velocity Mapping Toolbox: https://hydroacoustics.usgs.gov/movingboat/VMT/VMT.shtml

*Q-GIS: https://qgis.org/en/site/

*ARC-GIS: https://www.esri.com/en-us/arcgis/about-arcgis/overview

=Contact information=

[[Category:Devices]]

3D fish tracking system

2020-10-02T15:44:54Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 4: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 1). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 3a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 3b and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 4).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recording software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-10-02T15:44:23Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 4: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 1). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 3a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 3b and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 4).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-10-02T15:39:41Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 4: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 1). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 3a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 4).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

File:3d fish tracking fish tracks.jpg

2020-10-02T15:39:14Z

Ismailalbayrak:

{{Information
|author= Martin Detert
|source= VAW, ETH Zurich
|description= Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars.
}}

File:3d fish tracking 3d ouput.jpg

2020-10-02T15:36:38Z

Ismailalbayrak:

{{Information
|author= Martin Detert
|source= VAW, ETH Zurich
|description= (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish.
}}

File:3d fish tracking equipment.jpg

2020-10-02T15:35:47Z

Ismailalbayrak:

{{Information
|author= Martin Detert
|source=VAW, ETH Zurich
|description= (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection.
}}
w

File:3d fish tracking installation1.jpg

2020-10-02T15:34:42Z

Ismailalbayrak:

{{Information
|author= Claudia Beck
|source= VAW, ETH Zurich
|description= 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich
}}

File:3d fish tracking installation1.jpg

2020-10-02T09:00:24Z

Ismailalbayrak:

{{Information
|author= Claudia Beck
|source= VAW of ETH Zurich
|description= 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich
}}

File:Adcp wse.png

2020-10-02T08:58:11Z

Ismailalbayrak:

{{Information
|author= Mohammad Reza Maddahi
|source= VAW of ETH Zurich
|description= Water surface elevation along the power canal of HPP Schiffmühle (black line: DGPS data and red line: total station data).
}}

File:Adcp output.png

2020-10-02T08:54:27Z

Ismailalbayrak:

{{Information
|author= Stephan Kammerer
|source= VAW of ETH Zurich
|description= Exemplary depth-averaged velocity fields [cm/s] upstream of HPP Bannwil measured with boat-mounted ADCP at a discharge of 402 m3/s (background image: © 2018 swisstopo (JD 100041)), (FIThydro Deliverable 2.2)
}}

File:Adcp qboat.png

2020-10-02T08:52:47Z

Ismailalbayrak:

{{Information
|author= Ismail Albayrak
|source= Ismail Albayrak (ETH Zurich)
|description= Teledyne Marine Q-boat of VAW equipped with Riverpro ADCP and DGPS
}}

File:Adcp qboat.png

2020-10-02T08:51:44Z

Ismailalbayrak:

{{Information
|author= Ismail Albayrak
|source= Ismail Albayrak (ETH Zurich)
|description= ADCP and Q-boat in Rhone Glacier, Switzerland
}}

Schiffmühle test case

2020-09-30T15:44:22Z

Ismailalbayrak:

[[Category:Test cases]]
{{Fact box for Schiffmühle}}
{{Relevant SMTDs for Schiffmühle}}

=Introduction=
The hydropower plant (HPP) Schiffmühle is a run-of-the-river HPP located on the 35 km long stretch of the Limmat river in the communities of Untersiggenthal and Turgi near Baden, some 27 km downstream of Lake Zurich. Between lake Zurich and Schiffmühle there are seven HPPs, namely in flow direction Letten, Höngg , Dietikon, Wettingen, Aue, Oederlin and Kappelerhof. There are three more HPPs between HPP Schiffmühle and the junction with the Aare river, namely Turgi, Gebenstorf and Stroppel. The lowest and highest points of the Limmat river are 330 m and 406 m asl, respectively. The surface area of the whole catchment amounts to 2384 km2, of which 0.7 % are glaciated.

On river Limmat, the mean monthly discharge increases from March to June and then decreases from July to October. The mean annual discharge in 2015 was 89 m3/s, while the long-term average is 101 m3/s (1951-2015).

=About the hydropower plant=
At Schiffmühle, hydropower is exploited in two run-of-river HPPs, namely the main powerhouse located at the end of a headrace channel on the right shore and the residual flow HPP situated next to a flap gate at the upstream end of the weir on the left shore (see Gallery, layout of HPP Schiffmühle). In the scope of FIThydro, the residual flow HPP is the investigated case study HPP. This HPP has an installed capacity of 0.5 MW and a mean annual output of 1.9 GWh. It operates with a bevel gear bulb turbine.

===The Operator: Limmatkraftwerke AG (LKW)===
LKW produces environmentally friendly and local electricity from four main and two residual flow hydropower plants on river Limmat between Baden and Turgi. The company is owned by the Regionalwerke Holding AG Baden (60%), a local utility company, and the regional power company AEW (40%). The Regionalwerke AG Baden is responsible for the operation of the HPPs and all technical and energy management issues. The administrative and financial management are performed by Axpo AG. The average annual energy output is around 91 GWh. The company fulfills the standards according to ISO 9001 and the production of renewable energy is certified by TÜV SÜD Erzeugung EE.

=Pressures on the water body's ecosystem=
The river Limmat is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon rivers in Europe. The upstream migration of salmons (Salmo salar) in the Rhine catchment became almost impossible due to transverse structures such as hydropower plants. In the past few years a number of HPPs on the Rhine, Aare and Limmat rivers have been equipped with state-of-the-art fish passage facilities for upstream migration. However, downstream migration measures and sediment management strategies have hardly been realized. Furthermore, the Limmat river is highly influenced by HPPs and densely populated areas and considered as a heavily modified water body. The river has a moderate ecological potential. Various measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
All of the existing fish species in the Limmat river (at least 22 species) face potential mortality during their downstream migration, some of which also have difficulties to migrate upstream. Some of the most important species are: Eel (Anguilla anguilla), Brown trout, Common barbel (Barbus barbus), Grayling, Spirlin, Nase, Chub, Bleak.

===Downstream migration===
At the residual flow HPP Schiffmühle, an angled fish guidance structure with horizontal bars, termed Horizontal Bar Rack (HBR), has been implemented in 2013 to shield fish from the turbine intake and guide them into an adjacent bypass and to the tailwater. The rack is positioned parallel to the main flow to have a lateral intake. The HBR has a length of 14.6 m and a spacing of 20 mm between the bars, which are positioned in a vertical angle of 90°. At the end of the rack there is the bypass inlet with two openings in a vertical chamber in different water depths (close to the bottom and close to the surface). From there, a 25 cm diameter pipe bypasses the fish downstream, letting them out at about 0.20 m above the tailwater level. The discharge in the bypass is 170 l/s.

For monitoring downstream migrating fish, 1 PIT-tag antenna has been installed at the bypass pipe inlet.

===Upstream migration===
The residual flow HPP Schiffmühle has a combination of a nature-like and a technical fish pass (vertical slot) for upstream migration. The entrances of the nature-like fish pass and the vertical slot pass are located approx. 36 m and 2 m downstream of the turbine flow outlet, respectively. The technical and the nature-like fish passes merge at an elevation of 336.83 m a.s.l. (see figures in the Gallery). From there on upwards, fish use the nature-like pass. The total discharge in the fishway is 0.5 m3/s.

To monitor upstream migration and fish behavior in the migration facilities, 5 PIT-tag antennas have been installed in the technical vertical slot fish pass and in the nature-like pass.

===E-flow===
The residual flow HPP Schiffmühle supplies up to 14.00 m3/s of turbine water and 0.67 m3/s of the water in the fish passage facilities (upstream and downstream) to the downstream river reach as e-flow. Moreover, during high river discharges, additional water is supplied over the frontal weir at the HPP and over the side weir along the headrace channel to the residual flow reach.

===Sediment management===
An innovative vortex tube for bed load transport connectivity has been installed in 2002 in the headrace channel to guide bed load to the residual flow stretch of the Limmat river during floods (see: https://www.fithydro.wiki/index.php/Bedload_monitoring_system). Additionally, sediment can be flushed via the weir flap gate.

=Research objectives and tasks=
The studies at HPP Schiffmühle address various aspects of the upstream and downstream fish passes, downstream habitat and sediment transport. The findings of the studies have a wide range of applications for other HPPs and give answers to the fundamental questions on fish behavior at fish passes.
===Research tasks===
The research tasks and field studies conducted at HPP Schiffmühle are:

* Field campaign: hydraulics, habitat, attraction flow and Lateral Line Probe in upstream fish pass
* 3D numerical model of the HPP perimeter
* Fish monitoring
* Bed load monitoring at vortex tube
* Habitat and sediment modelling

=Results=
The flow conditions at the entrance of the nature-like fishway of the residual flow HPP Schiffmühle is more attractive for all monitored fish species than the flow condition at the entrance of the vertical slot fishway close to the draft tube outlet. However, the fish entrance efficiency is higher for the vertical slot fishway. Overall, the passage efficiency of the fish pass system is high (> 80 % for most species monitored), indicating an appropriate design and a good functionality.

Regarding downstream fish migration, velocity measurements and fish monitoring results show that the attraction flow to the bypass of the fish protection and guidance structure (Horizontal Bar Rack-Bypass System) is inefficient and needs to be upgraded and optimized. The results indicate that the design, location and operation of a fish guidance rack-bypass system is of prime importance for a successful implementation and a high guidance efficiency. Using a 3D numerical model, alternative bypass designs in terms of layout and inlet location have been investigated.

=Gallery=
<gallery mode=packed>
Schiffmühle_aerial.png|Aerial overview of Schiffmühle HPP; flow direction from top to bottom
schillmuhle_spillway.jpg|Residual flow HPP (left), flap-gated weir (centre) and headrace channel to the main HPP Schiffmühle (right); view to downstream
schillmuhle_fishway.jpg|Nature-like fishway at Schiffmühle HPP
Layout-Picture_Schiffmühle_CVAW_ETHZ_web-scaled.jpg|Layout of Schiffmühle HPP
schillmuhle_upstream-migration-devices_c_ETHZ_web-scaled.jpg|Overview of fish migration devices at Schiffmühle HPP
schiffmuhle_vertical_slot_fishway.jpg|Vertical slot fishway at Schiffmühle HPP
schiffmuhle_downstream-migration-devices_photo_2.jpg|Schematic of fish migration devices at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_photo_4.jpg|Outlet of sediment vortex tube at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_setup.jpg|Setup of the sediment vortex tube at Schiffmühle HPP
schiffmuhle_Calibration-of-sediment-monitoring-system-for-vortex-tube.jpg|Calibration of the sediment vortex tube monitoring system at Schiffmühle HPP
</gallery>

Schiffmühle test case

2020-09-30T15:40:21Z

Ismailalbayrak:

[[Category:Test cases]]
{{Fact box for Schiffmühle}}
{{Relevant SMTDs for Schiffmühle}}

=Introduction=
The hydropower plant (HPP) Schiffmühle is a run-of-the-river HPP located on the 35 km long stretch of the Limmat river in the communities of Untersiggenthal and Turgi near Baden, some 27 km downstream of Lake Zurich. Between lake Zurich and Schiffmühle there are seven HPPs, namely in flow direction Letten, Höngg , Dietikon, Wettingen, Aue, Oederlin and Kappelerhof. There are three more HPPs between HPP Schiffmühle and the junction with the Aare river, namely Turgi, Gebenstorf and Stroppel. The lowest and highest points of the Limmat river are 330 m and 406 m asl, respectively. The surface area of the whole catchment amounts to 2384 km2, of which 0.7 % are glaciated.

On river Limmat, the mean monthly discharge increases from March to June and then decreases from July to October. The mean annual discharge in 2015 was 89 m3/s, while the long-term average is 101 m3/s (1951-2015).

=About the hydropower plant=
At Schiffmühle, hydropower is exploited in two run-of-river HPPs, namely the main powerhouse located at the end of a headrace channel on the right shore and the residual flow HPP situated next to a flap gate at the upstream end of the weir on the left shore (see Gallery, layout of HPP Schiffmühle). In the scope of FIThydro, the residual flow HPP is the investigated case study HPP. This HPP has an installed capacity of 0.5 MW and a mean annual output of 1.9 GWh. It operates with a bevel gear bulb turbine.

===The Operator: Limmatkraftwerke AG (LKW)===
LKW produces environmentally friendly and local electricity from four main and two residual flow hydropower plants on river Limmat between Baden and Turgi. The company is owned by the Regionalwerke Holding AG Baden (60%), a local utility company, and the regional power company AEW (40%). The Regionalwerke AG Baden is responsible for the operation of the HPPs and all technical and energy management issues. The administrative and financial management are performed by Axpo AG. The average annual energy output is around 91 GWh. The company fulfills the standards according to ISO 9001 and the production of renewable energy is certified by TÜV SÜD Erzeugung EE.

=Pressures on the water body's ecosystem=
The river Limmat is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon rivers in Europe. The upstream migration of salmons (Salmo salar) in the Rhine catchment became almost impossible due to transverse structures such as hydropower plants. In the past few years a number of HPPs on the Rhine, Aare and Limmat rivers have been equipped with state-of-the-art fish passage facilities for upstream migration. However, downstream migration measures and sediment management strategies have hardly been realized. Furthermore, the Limmat river is highly influenced by HPPs and densely populated areas and considered as a heavily modified water body. The river has a moderate ecological potential. Various measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
All of the existing fish species in the Limmat river (at least 22 species) face potential mortality during their downstream migration, some of which also have difficulties to migrate upstream. Some of the most important species are: Eel (Anguilla anguilla), Brown trout, Common barbel (Barbus barbus), Grayling, Spirlin, Nase, Chub, Bleak.

===Downstream migration===
At the residual flow HPP Schiffmühle, an angled fish guidance structure with horizontal bars, termed Horizontal Bar Rack (HBR), has been implemented in 2013 to shield fish from the turbine intake and guide them into an adjacent bypass and to the tailwater. The rack is positioned parallel to the main flow to have a lateral intake. The HBR has a length of 14.6 m and a spacing of 20 mm between the bars, which are positioned in a vertical angle of 90°. At the end of the rack there is the bypass inlet with two openings in a vertical chamber in different water depths (close to the bottom and close to the surface). From there, a 25 cm diameter pipe bypasses the fish downstream, letting them out at about 0.20 m above the tailwater level. The discharge in the bypass is 170 l/s.

For monitoring downstream migrating fish, 1 PIT-tag antenna has been installed at the bypass pipe inlet.

===Upstream migration===
The residual flow HPP Schiffmühle has a combination of a nature-like and a technical fish pass (vertical slot) for upstream migration. The entrances of the nature-like fish pass and the vertical slot pass are located approx. 36 m and 2 m downstream of the turbine flow outlet, respectively. The technical and the nature-like fish passes merge at an elevation of 336.83 m a.s.l. (see figures in the Gallery). From there on upwards, fish use the nature-like pass. The total discharge in the fishway is 0.5 m3/s.

To monitor upstream migration and fish behavior in the migration facilities, 5 PIT-tag antennas have been installed in the technical vertical slot fish pass and in the nature-like pass.

===E-flow===
The residual flow HPP Schiffmühle supplies up to 14.00 m3/s of turbine water and 0.67 m3/s of the water in the fish passage facilities (upstream and downstream) to the downstream river reach as e-flow. Moreover, during high river discharges, additional water is supplied over the frontal weir at the HPP and over the side weir along the headrace channel to the residual flow reach.

===Sediment management===
An innovative vortex tube for bed load transport connectivity has been installed in 2002 in the headrace channel to guide bed load to the residual flow stretch of the Limmat river during floods. Additionally, sediment can be flushed via the weir flap gate.

=Research objectives and tasks=
The studies at HPP Schiffmühle address various aspects of the upstream and downstream fish passes, downstream habitat and sediment transport. The findings of the studies have a wide range of applications for other HPPs and give answers to the fundamental questions on fish behavior at fish passes.
===Research tasks===
The research tasks and field studies conducted at HPP Schiffmühle are:

* Field campaign: hydraulics, habitat, attraction flow and Lateral Line Probe in upstream fish pass
* 3D numerical model of the HPP perimeter
* Fish monitoring
* Bed load monitoring at vortex tube
* Habitat and sediment modelling

=Results=
The flow conditions at the entrance of the nature-like fishway of the residual flow HPP Schiffmühle is more attractive for all monitored fish species than the flow condition at the entrance of the vertical slot fishway close to the draft tube outlet. However, the fish entrance efficiency is higher for the vertical slot fishway. Overall, the passage efficiency of the fish pass system is high (> 80 % for most species monitored), indicating an appropriate design and a good functionality.

Regarding downstream fish migration, velocity measurements and fish monitoring results show that the attraction flow to the bypass of the fish protection and guidance structure (Horizontal Bar Rack-Bypass System) is inefficient and needs to be upgraded and optimized. The results indicate that the design, location and operation of a fish guidance rack-bypass system is of prime importance for a successful implementation and a high guidance efficiency. Using a 3D numerical model, alternative bypass designs in terms of layout and inlet location have been investigated.

=Gallery=
<gallery mode=packed>
Schiffmühle_aerial.png|Aerial overview of Schiffmühle HPP; flow direction from top to bottom
schillmuhle_spillway.jpg|Residual flow HPP (left), flap-gated weir (centre) and headrace channel to the main HPP Schiffmühle (right); view to downstream
schillmuhle_fishway.jpg|Nature-like fishway at Schiffmühle HPP
Layout-Picture_Schiffmühle_CVAW_ETHZ_web-scaled.jpg|Layout of Schiffmühle HPP
schillmuhle_upstream-migration-devices_c_ETHZ_web-scaled.jpg|Overview of fish migration devices at Schiffmühle HPP
schiffmuhle_vertical_slot_fishway.jpg|Vertical slot fishway at Schiffmühle HPP
schiffmuhle_downstream-migration-devices_photo_2.jpg|Schematic of fish migration devices at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_photo_4.jpg|Outlet of sediment vortex tube at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_setup.jpg|Setup of the sediment vortex tube at Schiffmühle HPP
schiffmuhle_Calibration-of-sediment-monitoring-system-for-vortex-tube.jpg|Calibration of the sediment vortex tube monitoring system at Schiffmühle HPP
</gallery>

Acoustic Doppler current profiler (ADCP)

2020-09-30T15:31:39Z

Ismailalbayrak:

=Quick summary=
[[file:adcp_example_units.png|thumb|250px|Figure 1: Examples of ADCPs: (a) Teledyne RiverPro with 5 beams (source: http://www.teledynemarine.com) and (b) Sontek M9 with 9 beams and S5 with 5 beams (source: https://www.sontek.com).]]
[[file:adcp_qboat.png|thumb|250px|Figure 2: Teledyne Marine Q-boat of VAW equipped with Riverpro ADCP and DGPS.]]
[[file:adcp_wse.png|thumb|250px|Figure 3: Water surface elevation along the power canal of HPP Schiffmühle (black line: DGPS data and red line: total station data).]]
[[file:adcp_workflow.png|thumb|250px|Figure 4: Workflow used for post-processing of ADCP data (click to expand).]]
[[file:adcp_output.png|thumb|250px|Figure 5: Depth averaged flow velocities upstream of the HPP Bannwil measured with the ADCP boat at a discharge of 402 m3/s (background image: © 2018 swisstopo (JD 100041)).]]

Developed by: Several Companies

Date: 2020

Type: [[:Category:Devices|Device]]

=Introduction=
Acoustic Doppler Current Profiler (ADCP) allows quick, easy and accurate measurements of 3D velocity time series and bathymetry, and computation of discharges in rivers, estuaries, lakes and reservoirs as well as oceans. ADCP data can be used for calibration of numerical models, hydraulic studies (for example, flow field around hydraulic structures), habitat quality assessment and modelling, hydro-morphologic surveys and sediment studies.

The ADCP is equipped with multi-beams (three up to nine beams, Figure 1), which emit acoustic energy at a known frequency and record the frequency of the acoustic energy backscattered by the particles in the water column. The velocity of the water flow along each beam is computed based on the change in the frequency of the emitted and backscattered acoustic energy, i.e. the Doppler shift. Detailed information on the ADCP working principle and its limitations are described by Simpson (2002). The ADCP beams are positioned to 20 or 30 degree away from the vertical axis. By using a simple trigonometry, 3D velocity components are computed from the Doppler shifts measured with three or four sonar beams. In the latter, a redundant, fourth beam is used to compute error
velocity, which is the difference between a velocity measured by one set of three beams and a velocity measured by another set of three beams at the same time (Simpson, 2002). The error velocity is used to evaluate the assumption of horizontal homogeneity. The frequency of the ultrasonic sound transmitted by commercially available ADCPs ranges from 30 kHz to 3000 KHz (Simpson, 2002). ADCP can be used at a fixed position, i.e. stationary, or mounted to a tethered boat, manned boat or a remote-controlled boat (Mueller et al., 2013). Non-stationary i.e. moving boat ADCP measurements yield the flow velocity and direction relative to the boat and hence the velocity of the boat should be accounted for by using either bottom tracking or global positioning system (GPS) to determine true flow velocity.

=Application=
Within the scope of FIThydro, high resolution 3D velocity, as well as bathymetry measurements, have been conducted using an ADCP mounted on a high speed remote-controlled boat at two hydropower plants (HPP) in Switzerland since the beginning of 2018. The models of the ADCP and the boat are River Pro 1200 kHz including piston style four-beam transducer with a 5th, independent 600 kHz vertical beam and Q-Boat purchased from Teledyne Marine, USA, respectively (Figure 2). An external Differential GPS (DGPS) system from A326 AtlasLink (Hemisphere) was used to accurately measure the positions of the ADCP. One set of the battery for the Q-boat allowed us to make measurements for 4 hours up to 10 hours depending on the flow velocity and field conditions i.e. temperature.

Compass calibration and moving bed tests are conducted before each ADCP measurement at the case study HPPs. The Test Case study HPP Schiffmühle is located on the 35 km long river Limmat between in Untersiggenthal and Turgi near Baden in Switzerland (see the Test Case presentation file for HPP Schiffmühle). Two transects of ADCP at each densely spaced cross-section along the river were enough but high accuracy of altitude data was required for the bathymetry measurements at the HPP and in general. The present DGPS system resulted in ±1m of errors in altitude measurements (Figure 3, black line). Therefore, use of a total station, which is time consuming, or real-time kinematic (RTK) GPS is recommended to accurately determine water surface and hence bathymetry (Figure 3, red line from total station measurements).

Furthermore, the test results from the HPP Bannwil located on River Aare in canton Bern indicated that averaging of at least 8 transects or even more at each cross-section is needed to obtain robust and smooth velocity field and accurate discharge data at highly turbulent and 3D flows occurring in rivers, turbine inlet and outlets or other hydraulic structures (see the Test Case presentation file for HPP Bannwil).

The ADCP data from both HPPs Schiffmühle and Bannwil are post-processed according to the workflow sketched in Figure 4 using the software WinRiver II (Teledyne software) and velocity mapping toolbox (VMT, Matlab based software for processing and visualizing ADCP data provided by U.S. Geological Survey). Figure 5 shows the depth-averaged velocities at the HPP Bannwil plotted with VMT. VMT can be used with the output files from Sontek ADCPs. For further data analysis and presentation on the maps like river bed changes, Q-GIS (free software) or ARC-GIS (Commercial software) are also recommended.

The present system based on the remote-controlled boat platform has advantages over the tethered boat ADCP application. These are less man-power needed, faster and more measurements in a shorter time, no flow disturbance and interference with beams and smoother movement of the boat.

=Relevant mitigation measures and test cases=
{{Suitable measures for Acoustic Doppler current profiler (ADCP)}}

=Other information=
The total costs for the Teledyne RiverPro 1200 kHz, Teledyne Q-boat and DGPS from Hemisphere Atlas link amount to approx. 22’000 €, 21’200 € and 3’340 € respectively. The costs of shipping, VAT, some mounting apparatus and long-range radio modem are excluded. For current costs of the equipment, we recommend to ask the corresponding supplier. Note that Q-boat can also house Sontek RiverSurveyor M9. Furthermore, a rugged laptop for field use is recommended.

=Relevant literature=
*Mueller, D.S., Wagner, C.R., Rehmel, M.S., Oberg, K.A., Rainville, F. (2013). Measuring discharge with acoustic Doppler current profilers from a moving boat (ver. 2.0, December 2013), U.S. Geological Survey Techniques and Methods, book 3, chap. http://dx.doi.org/10.3133/tm3A22.

*Simpson, M.R. (2002). Discharge measurements using a broadband acoustic Doppler current profiler. Open-file Report 2001-1, https://doi.org/10.3133/ofr011.

Links to the suppliers of equipment:

*Teledyne Marine, ADCP RiverPro: http://www.teledynemarine.com/riverpro-adcp?ProductLineID=13

*Teledyne Marine, Q-Boat: http://www.teledynemarine.com/Lists/Downloads/Q-Boat_1800_Datasheet.pdf

*Hemisphere Atlas DPS: https://hemispheregnss.com/Atlas/atlaslinke284a2-gnss-smart-antenna-1226

*Sontek ADCP M9: https://www.sontek.com/riversurveyor-s5-m9

Software for ADCP data analysis:

*Velocity Mapping Toolbox: https://hydroacoustics.usgs.gov/movingboat/VMT/VMT.shtml

*Q-GIS: https://qgis.org/en/site/

*ARC-GIS: https://www.esri.com/en-us/arcgis/about-arcgis/overview

=Contact information=

[[Category:Devices]]

Acoustic Doppler current profiler (ADCP)

2020-09-30T15:29:05Z

Ismailalbayrak:

=Quick summary=
[[file:adcp_example_units.png|thumb|250px|Figure 1: Examples of ADCPs: (a) Teledyne RiverPro with 5 beams (source: http://www.teledynemarine.com) and (b) Sontek M9 with 9 beams and S5 with 5 beams (source: https://www.sontek.com).]]
[[file:adcp_qboat.png|thumb|250px|Figure 2: Teledyne Marine Q-boat of VAW equipped with Riverpro ADCP and DGPS.]]
[[file:adcp_wse.png|thumb|250px|Figure 3: Water surface elevation along the power canal of HPP Schiffmühle (black line: DGPS data and red line: total station data).]]
[[file:adcp_workflow.png|thumb|250px|Figure 4: Workflow used for post-processing of ADCP data (click to expand).]]
[[file:adcp_output.png|thumb|250px|Figure 5: Depth averaged flow velocities upstream of the HPP Bannwil measured with the ADCP boat at a discharge of 402 m3/s (background image: © 2018 swisstopo (JD 100041)).]]

Developed by: Several Companies

Date: 2020

Type: [[:Category:Devices|Device]]

=Introduction=
Acoustic Doppler Current Profiler (ADCP) allows quick, easy and accurate measurements of 3D velocity time series and bathymetry, and computation of discharges in rivers, estuaries, lakes and reservoirs as well as oceans. ADCP data can be used for calibration of numerical models, hydraulic studies (for example, flow field around hydraulic structures), habitat quality assessment and modelling, hydro-morphologic surveys and sediment studies.

The ADCP is equipped with multi-beams (three up to nine beams, Figure 1), which emit acoustic energy at a known frequency and record the frequency of the acoustic energy backscattered by the particles in the water column. The velocity of the water flow along each beam is computed based on the change in the frequency of the emitted and backscattered acoustic energy, i.e. the Doppler shift. Detailed information on the ADCP working principle and its limitations are described by Simpson (2002). The ADCP beams are positioned to 20 or 30 degree away from the vertical axis. By using a simple trigonometry, 3D velocity components are computed from the Doppler shifts measured with three or four sonar beams. In the latter, a redundant, fourth beam is used to compute error
velocity, which is the difference between a velocity measured by one set of three beams and a velocity measured by another set of three beams at the same time (Simpson, 2002). The error velocity is used to evaluate the assumption of horizontal homogeneity. The frequency of the ultrasonic sound transmitted by commercially available ADCPs ranges from 30 kHz to 3000 KHz (Simpson, 2002). ADCP can be used at a fixed position, i.e. stationary, or mounted to a tethered boat, manned boat or a remote-controlled boat (Mueller et al., 2013). Non-stationary i.e. moving boat ADCP measurements yield the flow velocity and direction relative to the boat and hence the velocity of the boat should be accounted for by using either bottom tracking or global positioning system (GPS) to determine true flow velocity.

=Application=
Within the scope of FIThydro, high resolution 3D velocity, as well as bathymetry measurements, have been conducted using an ADCP mounted on a high speed remote-controlled boat at two hydropower plants (HPP) in Switzerland since the beginning of 2018. The models of the ADCP and the boat are River Pro 1200 kHz including piston style four-beam transducer with a 5th, independent 600 kHz vertical beam and Q-Boat purchased from Teledyne Marine, USA, respectively (Figure 2). An external Differential GPS (DGPS) system from A326 AtlasLink (Hemisphere) was used to accurately measure the positions of the ADCP. One set of the battery for the Q-boat allowed us to make measurements for 4 hours up to 10 hours depending on the flow velocity and field conditions i.e. temperature.

Compass calibration and moving bed tests are conducted before each ADCP measurement at the case study HPPs. The Test Case study HPP Schiffmühle is located on the 35 km long river Limmat between in Untersiggenthal and Turgi near Baden in Switzerland (see the Test Case presentation file for HPP Schiffmühle). Two transects of ADCP at each densely spaced cross-section along the river were enough but high accuracy of altitude data was required for the bathymetry measurements at the HPP and in general. The present DGPS system resulted in ±1m of errors in altitude measurements (Figure 3, black line). Therefore, use of a total station, which is time consuming, or real-time kinematic (RTK) GPS is recommended to accurately determine water surface and hence bathymetry (Figure 3, red line from total station measurements).

Furthermore, the test results from the HPP Bannwil located on River Aare in canton Bern indicated that averaging of at least 8 transects or even more at each cross-section is needed to obtain robust and smooth velocity field and accurate discharge data at highly turbulent and 3D flows occurring in rivers, turbine inlet and outlets or other hydraulic structures (see the Test Case presentation file for HPP Bannwil).

The ADCP data from both HPPs Schiffmühle and Bannwil are post-processed according to the workflow sketched in Figure 4 using the software WinRiver II (Teledyne software) and velocity mapping toolbox (VMT, Matlab based software for processing and visualizing ADCP data provided by U.S. Geological Survey). Figure 5 shows the depth-averaged velocities at the HPP Bannwil plotted with VMT. VMT can be used with the output files from Sontek ADCPs. For further data analysis and presentation on the maps like river bed changes, Q-GIS (free software) or ARC-GIS (Commercial software) are also recommended.

The present system based on the remote-controlled boat platform has advantages over the tethered boat ADCP application. These are less man-power needed, faster and more measurements in a shorter time, no flow disturbance and interference with beams and smoother movement of the boat.

=Relevant mitigation measures and test cases=
{{Suitable measures for Acoustic Doppler current profiler (ADCP)}}

=Other information=
The total costs for the geophone and accelerometer sensors amount to approx. 885-1'330 €. The costs for the field computer, the analog-digital-converter, and the 3G modem are approx. 5'300-6'200 €. The total costs for the Teledyne RiverPro 1200 kHz, Teledyne Q-boat and DGPS from Hemisphere Atlas link amount to approx. 22’000 €, 21’200 € and 3’340 € respectively. The costs of shipping, VAT, some mounting apparatus and long-range radio modem are excluded. For current costs of the equipment, we recommend to ask the corresponding supplier. Note that Q-boat can also house Sontek RiverSurveyor M9. Furthermore, a rugged laptop for field use is recommended.

=Relevant literature=
*Mueller, D.S., Wagner, C.R., Rehmel, M.S., Oberg, K.A., Rainville, F. (2013). Measuring discharge with acoustic Doppler current profilers from a moving boat (ver. 2.0, December 2013), U.S. Geological Survey Techniques and Methods, book 3, chap. http://dx.doi.org/10.3133/tm3A22.

*Simpson, M.R. (2002). Discharge measurements using a broadband acoustic Doppler current profiler. Open-file Report 2001-1, https://doi.org/10.3133/ofr011.

Links to the suppliers of equipment:

*Teledyne Marine, ADCP RiverPro: http://www.teledynemarine.com/riverpro-adcp?ProductLineID=13

*Teledyne Marine, Q-Boat: http://www.teledynemarine.com/Lists/Downloads/Q-Boat_1800_Datasheet.pdf

*Hemisphere Atlas DPS: https://hemispheregnss.com/Atlas/atlaslinke284a2-gnss-smart-antenna-1226

*Sontek ADCP M9: https://www.sontek.com/riversurveyor-s5-m9

Software for ADCP data analysis:

*Velocity Mapping Toolbox: https://hydroacoustics.usgs.gov/movingboat/VMT/VMT.shtml

*Q-GIS: https://qgis.org/en/site/

*ARC-GIS: https://www.esri.com/en-us/arcgis/about-arcgis/overview

=Contact information=

[[Category:Devices]]

Acoustic Doppler current profiler (ADCP)

2020-09-30T15:28:10Z

Ismailalbayrak: /* Quick summary */

=Quick summary=
[[file:adcp_example_units.png|thumb|250px|Figure 1: Exemples of ADCPs: (a) Teledyne RiverPro with 5 beams (source: http://www.teledynemarine.com) and (b) Sontek M9 with 9 beams and S5 with 5 beams (source: https://www.sontek.com).]]
[[file:adcp_qboat.png|thumb|250px|Figure 2: Teledyne Marine Q-boat of VAW equipped with Riverpro ADCP and DGPS.]]
[[file:adcp_wse.png|thumb|250px|Figure 3: Water surface elevation along the power canal of HPP Schiffmühle (black line: DGPS data and red line: total station data).]]
[[file:adcp_workflow.png|thumb|250px|Figure 4: Workflow used for post-processing of ADCP data (click to expand).]]
[[file:adcp_output.png|thumb|250px|Figure 5: Depth averaged flow velocities upstream of the HPP Bannwil measured with the ADCP boat at a discharge of 402 m3/s (background image: © 2018 swisstopo (JD 100041)).]]

Developed by: Several Companies

Date: 2020

Type: [[:Category:Devices|Device]]

=Introduction=
Acoustic Doppler Current Profiler (ADCP) allows quick, easy and accurate measurements of 3D velocity time series and bathymetry, and computation of discharges in rivers, estuaries, lakes and reservoirs as well as oceans. ADCP data can be used for calibration of numerical models, hydraulic studies (for example, flow field around hydraulic structures), habitat quality assessment and modelling, hydro-morphologic surveys and sediment studies.

The ADCP is equipped with multi-beams (three up to nine beams, Figure 1), which emit acoustic energy at a known frequency and record the frequency of the acoustic energy backscattered by the particles in the water column. The velocity of the water flow along each beam is computed based on the change in the frequency of the emitted and backscattered acoustic energy, i.e. the Doppler shift. Detailed information on the ADCP working principle and its limitations are described by Simpson (2002). The ADCP beams are positioned to 20 or 30 degree away from the vertical axis. By using a simple trigonometry, 3D velocity components are computed from the Doppler shifts measured with three or four sonar beams. In the latter, a redundant, fourth beam is used to compute error
velocity, which is the difference between a velocity measured by one set of three beams and a velocity measured by another set of three beams at the same time (Simpson, 2002). The error velocity is used to evaluate the assumption of horizontal homogeneity. The frequency of the ultrasonic sound transmitted by commercially available ADCPs ranges from 30 kHz to 3000 KHz (Simpson, 2002). ADCP can be used at a fixed position, i.e. stationary, or mounted to a tethered boat, manned boat or a remote-controlled boat (Mueller et al., 2013). Non-stationary i.e. moving boat ADCP measurements yield the flow velocity and direction relative to the boat and hence the velocity of the boat should be accounted for by using either bottom tracking or global positioning system (GPS) to determine true flow velocity.

=Application=
Within the scope of FIThydro, high resolution 3D velocity, as well as bathymetry measurements, have been conducted using an ADCP mounted on a high speed remote-controlled boat at two hydropower plants (HPP) in Switzerland since the beginning of 2018. The models of the ADCP and the boat are River Pro 1200 kHz including piston style four-beam transducer with a 5th, independent 600 kHz vertical beam and Q-Boat purchased from Teledyne Marine, USA, respectively (Figure 2). An external Differential GPS (DGPS) system from A326 AtlasLink (Hemisphere) was used to accurately measure the positions of the ADCP. One set of the battery for the Q-boat allowed us to make measurements for 4 hours up to 10 hours depending on the flow velocity and field conditions i.e. temperature.

Compass calibration and moving bed tests are conducted before each ADCP measurement at the case study HPPs. The Test Case study HPP Schiffmühle is located on the 35 km long river Limmat between in Untersiggenthal and Turgi near Baden in Switzerland (see the Test Case presentation file for HPP Schiffmühle). Two transects of ADCP at each densely spaced cross-section along the river were enough but high accuracy of altitude data was required for the bathymetry measurements at the HPP and in general. The present DGPS system resulted in ±1m of errors in altitude measurements (Figure 3, black line). Therefore, use of a total station, which is time consuming, or real-time kinematic (RTK) GPS is recommended to accurately determine water surface and hence bathymetry (Figure 3, red line from total station measurements).

Furthermore, the test results from the HPP Bannwil located on River Aare in canton Bern indicated that averaging of at least 8 transects or even more at each cross-section is needed to obtain robust and smooth velocity field and accurate discharge data at highly turbulent and 3D flows occurring in rivers, turbine inlet and outlets or other hydraulic structures (see the Test Case presentation file for HPP Bannwil).

The ADCP data from both HPPs Schiffmühle and Bannwil are post-processed according to the workflow sketched in Figure 4 using the software WinRiver II (Teledyne software) and velocity mapping toolbox (VMT, Matlab based software for processing and visualizing ADCP data provided by U.S. Geological Survey). Figure 5 shows the depth-averaged velocities at the HPP Bannwil plotted with VMT. VMT can be used with the output files from Sontek ADCPs. For further data analysis and presentation on the maps like river bed changes, Q-GIS (free software) or ARC-GIS (Commercial software) are also recommended.

The present system based on the remote-controlled boat platform has advantages over the tethered boat ADCP application. These are less man-power needed, faster and more measurements in a shorter time, no flow disturbance and interference with beams and smoother movement of the boat.

=Relevant mitigation measures and test cases=
{{Suitable measures for Acoustic Doppler current profiler (ADCP)}}

=Other information=
The total costs for the geophone and accelerometer sensors amount to approx. 885-1'330 €. The costs for the field computer, the analog-digital-converter, and the 3G modem are approx. 5'300-6'200 €. The total costs for the Teledyne RiverPro 1200 kHz, Teledyne Q-boat and DGPS from Hemisphere Atlas link amount to approx. 22’000 €, 21’200 € and 3’340 € respectively. The costs of shipping, VAT, some mounting apparatus and long-range radio modem are excluded. For current costs of the equipment, we recommend to ask the corresponding supplier. Note that Q-boat can also house Sontek RiverSurveyor M9. Furthermore, a rugged laptop for field use is recommended.

=Relevant literature=
*Mueller, D.S., Wagner, C.R., Rehmel, M.S., Oberg, K.A., Rainville, F. (2013). Measuring discharge with acoustic Doppler current profilers from a moving boat (ver. 2.0, December 2013), U.S. Geological Survey Techniques and Methods, book 3, chap. http://dx.doi.org/10.3133/tm3A22.

*Simpson, M.R. (2002). Discharge measurements using a broadband acoustic Doppler current profiler. Open-file Report 2001-1, https://doi.org/10.3133/ofr011.

Links to the suppliers of equipment:

*Teledyne Marine, ADCP RiverPro: http://www.teledynemarine.com/riverpro-adcp?ProductLineID=13

*Teledyne Marine, Q-Boat: http://www.teledynemarine.com/Lists/Downloads/Q-Boat_1800_Datasheet.pdf

*Hemisphere Atlas DPS: https://hemispheregnss.com/Atlas/atlaslinke284a2-gnss-smart-antenna-1226

*Sontek ADCP M9: https://www.sontek.com/riversurveyor-s5-m9

Software for ADCP data analysis:

*Velocity Mapping Toolbox: https://hydroacoustics.usgs.gov/movingboat/VMT/VMT.shtml

*Q-GIS: https://qgis.org/en/site/

*ARC-GIS: https://www.esri.com/en-us/arcgis/about-arcgis/overview

=Contact information=

[[Category:Devices]]

3D fish tracking system

2020-09-30T15:26:17Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 1). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 3a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 4).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-09-30T15:25:03Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 1). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 14a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 15).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-09-30T15:22:17Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 1). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 14a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 14a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 15).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-09-30T15:19:37Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 12, right). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 14a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 14a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 15).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

File:3d fish tracking installation1.jpg

2020-09-30T15:17:09Z

Ismailalbayrak: Ismailalbayrak uploaded a new version of File:3d fish tracking installation1.jpg

3D fish tracking system

2020-09-30T15:14:09Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system (empty of water) installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 1). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 2a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 2b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 2c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 12, right). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 14a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 14a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 15).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-09-30T15:13:32Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system (empty of water) installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 1) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 2). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 13a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 13b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 13c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 12, right). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 14a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 14a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 15).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

3D fish tracking system

2020-09-30T15:12:34Z

Ismailalbayrak:

{{Note|This technology has been developed in the FIThydro project! See [[Innovative technologies from FIThydro]] for a complete list.|reminder}}

=Quick summary=
[[file:3d_fish_tracking_installation1.jpg|thumb|250px|Figure 1: 3D fish tracking system (empty of water) installed in the etho-hydraulic flume at VAW of ETH Zurich (source: VAW)]]
[[file:3d_fish_tracking_equipment.jpg|thumb|250px|Figure 2: (a) Camera (acA2000-50gmNIR, Basler) with lens (FE185C086HA-1, Fujifilm), (b) waterproof housing for the camera and lens (Autovimation), (c) high performance computer for camera recording and network switch for camera connection (source: VAW).]]
[[file:3d_fish_tracking_3d_ouput.jpg|thumb|250px|Figure 3: (a) Stereo view of a camera pair, (b) three detected fish and noise, (c) 2D tracks of three fish (source: VAW).]]
[[file:3d_fish_tracking_fish_tracks.jpg|thumb|250px|Figure 5: Top view of 3D tracks of three fish from an etho-hydraulic test of fish guidance structure with horizontal bars (source: VAW).]]

Date: 2018

Developed by: VAW of ETH Zurich

Type: [[:Category:Devices|Device]], [[:Category:Methods|Method]]

=Introduction=
Laboratory investigations with live-fish, i.e. so-called etho-hydraulic tests, serve to understand interactions between the hydraulics of fish protection technologies and fish behaviour and hence to improve the current design of fish passages or develop new technologies. For laboratory application, VAW of ETH Zurich developed a three dimensional (3D) fish tracking system consisting of synchronous vertically submerged cameras and a MATLAB-based 3D tracking software to determine fish locations in the flow from the recorded videos (Figure 1).

Typically, the behaviour of aquatic fauna is documented by manual protocol written down by biologists and (optional) supplementary video recording. The main drawbacks of both techniques are (i) time consuming, (ii) low time resolution, (iii) low spatial resolution, and (iv) providing only qualitative information. The present 3D fish tracking system overcomes such drawbacks by automatically and accurately providing 3D swimming tracks on a larger metric space at a milliseconds time resolution.

The software tracks several fish in 3D. Swimming path-time diagrams give a distinct ‘big picture’ of the fish movement, which helps to identify fish preferred and disliked regions. Furthermore, detailed 3D path analyses of fish interactions and fish velocities are provided as well. The details of the system are documented below. Although the 3D fish tracking system is developed for laboratory use, it may be applied in an adapted version in the field to monitor fish movements or counting, as long as the visual observation is not compromised by turbidity.

=Application=
Within the scope of FIThydro, VAW investigates two types of fish guidance structures (FGS), namely with horizontal (Figure 12) and vertical curved bars. These FGSs are tested with six different fish species under various hydraulic conditions to evaluate their fish guidance efficiencies and to understand fish behaviour. To this end, the 3D fish tracking system is further developed and tested in these etho-hdyraulic (live-fish) investigations. The present system is similar to that currently used by the German Federal Institute for Hydraulic Engineering (BAW) in Karlsruhe together with the German Federal Institute of Hydrology (BfG, 2018; Detert et al., 2018).

The present system consists of up to five cameras arranged in a streamwise series facing vertically upwards through the water surface, each with a distance of 1.5 m (Figure 13). Model acA2000-50gmNIR cameras from Basler are used and equipped with a 185° fisheye lens of FE185C086HA-1 (Fujifilm) (Figure 13a). The camera resolution is 3 MPx. Each camera and lens are waterproofed using a housing from Autovimation (Figure 13b). A GigE Vision 2.0 network with a Precision Time Protocol (PTP) IEEE1588 provided synchronous measurements with frame rates kept constant at 20 fps (Figure 13c). For larger control volume and longer areas, the actual system including the network switch and the high performance PC can theoretically be equipped with up to 48 cameras. However, the frame rate will be lower then.

An adapted software by Fujifilm Switzerland is used to set-up cameras and record videos. The etho-hydraulic flume is illuminated with 7x1000 W halogen lamps (Figure 12, right). Calibration of the system is essential and made in three steps: finding intrinsic and extrinsic parameters for each of the five cameras using a checkboard, calibrating five stereo cameras according to the overlapping views of camera pairs, and finally performing a rigid transformation of all stereo camera pairs to a global flume coordinate system (Figure 14a, Detert et al., 2018).

3D fish tracking is based on the detection of moving fish in each frame and associating the detections corresponding to the same fish over time. These are done by using a background subtraction algorithm and a Karman filter in MATLAB (Detert et al., 2018). The primary results of motion-based tracking are tracks in a distorted and uncalibrated 2D image frame coordinate system for each camera. Figure 14a and c show the three detected fish and noises caused by reflections from the glass window and their 2D tracks over time. After undistorting such frames and stereo calibrating the cameras, the 2D fish tracks are transferred to a 3D metric-space according to their epipolar geometry based on the camera parameters derived from the calibration (Figure 15).

The etho-hydraulic tests were done for a flow depth of 90 cm, flume width of 150 cm, distance of 150 cm between the cameras and average flow velocities up to 0.7 m/s. Under such conditions, the 3D fish tracking system provided fish positions in 3D with an accuracy of about ±5 cm and 20 fps. The challenges for a successful implementation of the system are: assignment of individual fish to the tracks, constant illumination of the flow, camera distortion, air bubbles and suspended sediment and humid conditions for the cameras.
Overall, despite some shortcomings such as noise due to reflections from the glass windows, the 3D fish tracking system works well, provides important information on fish behaviour affected by fish guidance structures and has the potential for further etho-hydraulic studies.

=Relevant mitigation measures and test cases=
{{Suitable measures for 3D fish tracking system}}

=Other information=
The total costs of the present system is approx. 40’000 USD=35’000 € including camera set-up and recoding software. For current costs of the equipment, we recommend to ask the corresponding supplier listed below. Note that a cheaper camera and lens set-up can significantly reduce the total cost of the system. The MATLAB-based 3D tracking code developed by VAW will be freely available.

Links to the suppliers of equipment:

*[https://www.baslerweb.com/en/products/cameras/area-scan-cameras/ace/aca2000-50gmnir/ Basler camera]

*[http://www.fujifilm.com/products/optical_devices/pdf/cctv/fa/fisheye/fe185c086ha-1.pdf Fujifilm lens]

*[https://www.autovimation.com/index.php/en/selection-guide-enclosures Camera waterproof enclosure]

Software for 3D fish tracking:

*Available on request.

=Relevant literature=
*BfG (German Federal Institute of Hydrology), 2018. The behaviour of fish in fishways – BfG and BAW’s ethohydraulic tests. Annual report of 2016/2017, pp.43. https://doi.org/10.5675/bfg-jahresbericht_2016/2017.

*Detert, M., Schütz, C., Czerny, R. (2018). Development and test of a 3D fish-tracking videometry system for an experimenal flume. In Proc. River Flow 2018 - Ninth International Conference on Fluvial Hydraulics, E3S Web of Conferences 40: 03018. https://doi.org/10.1051/e3sconf/20184003018

[[Category:Devices]][[Category:Methods]][[Category:developed in FIThydro]]

Schiffmühle test case

2020-05-08T14:09:05Z

Ismailalbayrak: /* Research objectives and tasks */

[[Category:Test cases]]
{{Fact box for Schiffmühle}}
{{Relevant SMTDs for Schiffmühle}}

=Introduction=
The hydropower plant (HPP) Schiffmühle is a run-of-the-river HPP located on the 35 km long stretch of the Limmat river in the communities of Untersiggenthal and Turgi near Baden, some 27 km downstream of Lake Zurich. Between lake Zurich and Schiffmühle there are seven HPPs, namely in flow direction Letten, Höngg , Dietikon, Wettingen, Aue, Oederlin and Kappelerhof. There are three more HPPs between HPP Schiffmühle and the junction with the Aare river, namely Turgi, Gebenstorf and Stroppel. The lowest and highest points of the Limmat river are 330 m and 406 m asl, respectively. The surface area of the whole catchment amounts to 2384 km2, of which 0.7 % are glaciated.

On river Limmat, the mean monthly discharge increases from March to June and then decreases from July to October. The annual discharge in 2015 was 89 m3/s, while the long-term average is 101 m3/s (1951-2015).

=About the hydropower plant=
At Schiffmühle, hydropower is exploited in two run-of-river HPPs, namely the main powerhouse located at the end of a headrace channel on the right shore and the residual flow HPP situated next to a flap gate at the upstream end of the weir on the left shore (see Gallery, layout of HPP Schiffmühle). In the scope of FIThydro, the residual flow HPP is the investigated case study HPP. This HPP has an installed capacity of 0.5 MW and a mean annual output of 1.9 GWh. It operates with a bevel gear bulb turbine.

===The Operator: Limmatkraftwerke AG (LKW)===
LKW produces environmentally friendly and local electricity from four main and two residual flow hydropower plants on river Limmat between Baden and Turgi. The company is owned by the Regionalwerke Holding AG Baden (60%), a local utility company, and the regional power company AEW (40%). The Regionalwerke AG Baden is responsible for the operation of the HPPs and all technical and energy management issues. The administrative and financial management are performed by Axpo AG. The average annual energy output is around 91 GWh. The company fulfills the standards according to ISO 9001 and the production of renewable energy is certified by TÜV SÜD Erzeugung EE.

=Pressures on the water body's ecosystem=
The river Limmat is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon rivers in Europe. The upstream migration of salmons (Salmo salar) in the Rhine catchment became almost impossible due to transverse structures such as hydropower plants. In the past few years a number of HPPs on the Rhine, Aare and Limmat rivers have been equipped with state-of-the-art fish passage facilities for upstream migration. However, downstream migration measures and sediment management strategies have hardly been realized. Furthermore, the Limmat river is highly influenced by HPPs and densely populated areas and considered as a heavily modified water body. The river has a moderate ecological potential. Various measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
All of the existing fish species in the Limmat river (at least 22 species) face potential mortality during their downstream migration, some of which also have difficulties to migrate upstream. Some of the most important species are: Eel (Anguilla anguilla), Brown trout, Common barbel (Barbus barbus), Grayling, Spirlin, Nase, Chub, Bleak.

===Downstream migration===
At the residual flow HPP Schiffmühle, an angled fish guidance structure with horizontal bars, termed Horizontal Bar Rack (HBR), has been implemented in 2013 to shield fish from the turbine intake and guide them into an adjacent bypass and to the tailwater. The rack is positioned parallel to the main flow to have a lateral intake. The HBR has a length of 14.6 m and a spacing of 20 mm between the bars, which are positioned in a vertical angle of 90°. At the end of the rack there is the bypass inlet with two openings in a vertical chamber in different water depths (close to the bottom and close to the surface). From there, a 25 cm diameter pipe bypasses the fish downstream, letting them out at about 0.20 m above the tailwater level. The discharge in the bypass is 170 l/s.

For monitoring downstream migrating fish, 1 PIT-tag antenna has been installed at the bypass pipe inlet.

===Upstream migration===
The residual flow HPP Schiffmühle has a combination of a nature-like and a technical fish pass (vertical slot) for upstream migration. The entrances of the nature-like fish pass and the vertical slot pass are located approx. 36 m and 2 m downstream of the turbine flow outlet, respectively. The technical and the nature-like fish passes merge at an elevation of 336.83 m a.s.l. (see figures in the Gallery). From there on upwards, fish use the nature-like pass. The total discharge in the fishway is 0.5 m3/s.

To monitor upstream migration and fish behavior in the migration facilities, 5 PIT-tag antennas have been installed in the technical vertical slot fish pass and in the nature-like pass.

===E-flow===
The residual flow HPP Schiffmühle supplies up to 14.00 m3/s of turbine water and 0.67 m3/s of the water in the fish passage facilities (upstream and downstream) to the downstream river reach as e-flow. Moreover, during high river discharges, additional water is supplied over the frontal weir at the HPP and over the side weir along the headrace channel to the residual flow reach.

===Sediment management===
An innovative vortex tube for bed load transport connectivity has been installed in 2002 in the headrace channel to guide bed load to the residual flow stretch of the Limmat river during floods. Additionally, sediment can be flushed via the weir flap gate.

=Research objectives and tasks=
The studies at HPP Schiffmühle address various aspects of the upstream and downstream fish passes, downstream habitat and sediment transport. The findings of the studies have a wide range of applications for other HPPs and give answers to the fundamental questions on fish behavior at fish passes.
===Research tasks===
The research tasks and field studies conducted at HPP Schiffmühle are:

* Field campaign: hydraulics, habitat, attraction flow and Lateral Line Probe in upstream fish pass
* 3D numerical model of the HPP perimeter
* Fish monitoring
* Bed load monitoring at vortex tube
* Habitat and sediment modelling

=Results=
The flow conditions at the entrance of the nature-like fishway of the residual flow HPP Schiffmühle is more attractive for all monitored fish species than the flow condition at the entrance of the vertical slot fishway close to the draft tube outlet. However, the fish entrance efficiency is higher for the vertical slot fishway. Overall, the passage efficiency of the fish pass system is high (> 80 % for most species monitored), indicating an appropriate design and a good functionality.

Regarding downstream fish migration, velocity measurements and fish monitoring results show that the attraction flow to the bypass of the fish protection and guidance structure (Horizontal Bar Rack-Bypass System) is inefficient and needs to be upgraded and optimized. The results indicate that the design, location and operation of a fish guidance rack-bypass system is of prime importance for a successful implementation and a high guidance efficiency. Using a 3D numerical model, alternative bypass designs in terms of layout and inlet location have been investigated.

=Gallery=
<gallery mode=packed>
Schiffmühle_aerial.png|Aerial overview of Schiffmühle HPP; flow direction from top to bottom
schillmuhle_spillway.jpg|Residual flow HPP (left), flap-gated weir (centre) and headrace channel to the main HPP Schiffmühle (right); view to downstream
schillmuhle_fishway.jpg|Nature-like fishway at Schiffmühle HPP
Layout-Picture_Schiffmühle_CVAW_ETHZ_web-scaled.jpg|Layout of Schiffmühle HPP
schillmuhle_upstream-migration-devices_c_ETHZ_web-scaled.jpg|Overview of fish migration devices at Schiffmühle HPP
schiffmuhle_vertical_slot_fishway.jpg|Vertical slot fishway at Schiffmühle HPP
schiffmuhle_downstream-migration-devices_photo_2.jpg|Schematic of fish migration devices at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_photo_4.jpg|Outlet of sediment vortex tube at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_setup.jpg|Setup of the sediment vortex tube at Schiffmühle HPP
schiffmuhle_Calibration-of-sediment-monitoring-system-for-vortex-tube.jpg|Calibration of the sediment vortex tube monitoring system at Schiffmühle HPP
</gallery>

Schiffmühle test case

2020-05-08T14:07:26Z

Ismailalbayrak: /* E-flow */

[[Category:Test cases]]
{{Fact box for Schiffmühle}}
{{Relevant SMTDs for Schiffmühle}}

=Introduction=
The hydropower plant (HPP) Schiffmühle is a run-of-the-river HPP located on the 35 km long stretch of the Limmat river in the communities of Untersiggenthal and Turgi near Baden, some 27 km downstream of Lake Zurich. Between lake Zurich and Schiffmühle there are seven HPPs, namely in flow direction Letten, Höngg , Dietikon, Wettingen, Aue, Oederlin and Kappelerhof. There are three more HPPs between HPP Schiffmühle and the junction with the Aare river, namely Turgi, Gebenstorf and Stroppel. The lowest and highest points of the Limmat river are 330 m and 406 m asl, respectively. The surface area of the whole catchment amounts to 2384 km2, of which 0.7 % are glaciated.

On river Limmat, the mean monthly discharge increases from March to June and then decreases from July to October. The annual discharge in 2015 was 89 m3/s, while the long-term average is 101 m3/s (1951-2015).

=About the hydropower plant=
At Schiffmühle, hydropower is exploited in two run-of-river HPPs, namely the main powerhouse located at the end of a headrace channel on the right shore and the residual flow HPP situated next to a flap gate at the upstream end of the weir on the left shore (see Gallery, layout of HPP Schiffmühle). In the scope of FIThydro, the residual flow HPP is the investigated case study HPP. This HPP has an installed capacity of 0.5 MW and a mean annual output of 1.9 GWh. It operates with a bevel gear bulb turbine.

===The Operator: Limmatkraftwerke AG (LKW)===
LKW produces environmentally friendly and local electricity from four main and two residual flow hydropower plants on river Limmat between Baden and Turgi. The company is owned by the Regionalwerke Holding AG Baden (60%), a local utility company, and the regional power company AEW (40%). The Regionalwerke AG Baden is responsible for the operation of the HPPs and all technical and energy management issues. The administrative and financial management are performed by Axpo AG. The average annual energy output is around 91 GWh. The company fulfills the standards according to ISO 9001 and the production of renewable energy is certified by TÜV SÜD Erzeugung EE.

=Pressures on the water body's ecosystem=
The river Limmat is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon rivers in Europe. The upstream migration of salmons (Salmo salar) in the Rhine catchment became almost impossible due to transverse structures such as hydropower plants. In the past few years a number of HPPs on the Rhine, Aare and Limmat rivers have been equipped with state-of-the-art fish passage facilities for upstream migration. However, downstream migration measures and sediment management strategies have hardly been realized. Furthermore, the Limmat river is highly influenced by HPPs and densely populated areas and considered as a heavily modified water body. The river has a moderate ecological potential. Various measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
All of the existing fish species in the Limmat river (at least 22 species) face potential mortality during their downstream migration, some of which also have difficulties to migrate upstream. Some of the most important species are: Eel (Anguilla anguilla), Brown trout, Common barbel (Barbus barbus), Grayling, Spirlin, Nase, Chub, Bleak.

===Downstream migration===
At the residual flow HPP Schiffmühle, an angled fish guidance structure with horizontal bars, termed Horizontal Bar Rack (HBR), has been implemented in 2013 to shield fish from the turbine intake and guide them into an adjacent bypass and to the tailwater. The rack is positioned parallel to the main flow to have a lateral intake. The HBR has a length of 14.6 m and a spacing of 20 mm between the bars, which are positioned in a vertical angle of 90°. At the end of the rack there is the bypass inlet with two openings in a vertical chamber in different water depths (close to the bottom and close to the surface). From there, a 25 cm diameter pipe bypasses the fish downstream, letting them out at about 0.20 m above the tailwater level. The discharge in the bypass is 170 l/s.

For monitoring downstream migrating fish, 1 PIT-tag antenna has been installed at the bypass pipe inlet.

===Upstream migration===
The residual flow HPP Schiffmühle has a combination of a nature-like and a technical fish pass (vertical slot) for upstream migration. The entrances of the nature-like fish pass and the vertical slot pass are located approx. 36 m and 2 m downstream of the turbine flow outlet, respectively. The technical and the nature-like fish passes merge at an elevation of 336.83 m a.s.l. (see figures in the Gallery). From there on upwards, fish use the nature-like pass. The total discharge in the fishway is 0.5 m3/s.

To monitor upstream migration and fish behavior in the migration facilities, 5 PIT-tag antennas have been installed in the technical vertical slot fish pass and in the nature-like pass.

===E-flow===
The residual flow HPP Schiffmühle supplies up to 14.00 m3/s of turbine water and 0.67 m3/s of the water in the fish passage facilities (upstream and downstream) to the downstream river reach as e-flow. Moreover, during high river discharges, additional water is supplied over the frontal weir at the HPP and over the side weir along the headrace channel to the residual flow reach.

===Sediment management===
An innovative vortex tube for bed load transport connectivity has been installed in 2002 in the headrace channel to guide bed load to the residual flow stretch of the Limmat river during floods. Additionally, sediment can be flushed via the weir flap gate.

=Research objectives and tasks=
The studies at HPP Schiffmühle address various aspects of the upstream and downstream fish passes, downstream habitat and sediment transport. The findings of the studies will have a wide range of applications for other HPPs and will give answers to the fundamental questions on fish behavior at fish passes.
===Research tasks===
The research tasks and field studies conducted at HPP Schiffmühle are:

* Field campaign: hydraulics, habitat, attraction flow and Lateral Line Probe in upstream fish pass
* 3D numerical model of the HPP perimeter
* Fish monitoring
* Bed load monitoring at vortex tube
* Habitat and sediment modelling

=Results=
The flow conditions at the entrance of the nature-like fishway of the residual flow HPP Schiffmühle is more attractive for all monitored fish species than the flow condition at the entrance of the vertical slot fishway close to the draft tube outlet. However, the fish entrance efficiency is higher for the vertical slot fishway. Overall, the passage efficiency of the fish pass system is high (> 80 % for most species monitored), indicating an appropriate design and a good functionality.

Regarding downstream fish migration, velocity measurements and fish monitoring results show that the attraction flow to the bypass of the fish protection and guidance structure (Horizontal Bar Rack-Bypass System) is inefficient and needs to be upgraded and optimized. The results indicate that the design, location and operation of a fish guidance rack-bypass system is of prime importance for a successful implementation and a high guidance efficiency. Using a 3D numerical model, alternative bypass designs in terms of layout and inlet location have been investigated.

=Gallery=
<gallery mode=packed>
Schiffmühle_aerial.png|Aerial overview of Schiffmühle HPP; flow direction from top to bottom
schillmuhle_spillway.jpg|Residual flow HPP (left), flap-gated weir (centre) and headrace channel to the main HPP Schiffmühle (right); view to downstream
schillmuhle_fishway.jpg|Nature-like fishway at Schiffmühle HPP
Layout-Picture_Schiffmühle_CVAW_ETHZ_web-scaled.jpg|Layout of Schiffmühle HPP
schillmuhle_upstream-migration-devices_c_ETHZ_web-scaled.jpg|Overview of fish migration devices at Schiffmühle HPP
schiffmuhle_vertical_slot_fishway.jpg|Vertical slot fishway at Schiffmühle HPP
schiffmuhle_downstream-migration-devices_photo_2.jpg|Schematic of fish migration devices at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_photo_4.jpg|Outlet of sediment vortex tube at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_setup.jpg|Setup of the sediment vortex tube at Schiffmühle HPP
schiffmuhle_Calibration-of-sediment-monitoring-system-for-vortex-tube.jpg|Calibration of the sediment vortex tube monitoring system at Schiffmühle HPP
</gallery>

Schiffmühle test case

2020-05-08T14:06:48Z

Ismailalbayrak: /* Upstream migration */

[[Category:Test cases]]
{{Fact box for Schiffmühle}}
{{Relevant SMTDs for Schiffmühle}}

=Introduction=
The hydropower plant (HPP) Schiffmühle is a run-of-the-river HPP located on the 35 km long stretch of the Limmat river in the communities of Untersiggenthal and Turgi near Baden, some 27 km downstream of Lake Zurich. Between lake Zurich and Schiffmühle there are seven HPPs, namely in flow direction Letten, Höngg , Dietikon, Wettingen, Aue, Oederlin and Kappelerhof. There are three more HPPs between HPP Schiffmühle and the junction with the Aare river, namely Turgi, Gebenstorf and Stroppel. The lowest and highest points of the Limmat river are 330 m and 406 m asl, respectively. The surface area of the whole catchment amounts to 2384 km2, of which 0.7 % are glaciated.

On river Limmat, the mean monthly discharge increases from March to June and then decreases from July to October. The annual discharge in 2015 was 89 m3/s, while the long-term average is 101 m3/s (1951-2015).

=About the hydropower plant=
At Schiffmühle, hydropower is exploited in two run-of-river HPPs, namely the main powerhouse located at the end of a headrace channel on the right shore and the residual flow HPP situated next to a flap gate at the upstream end of the weir on the left shore (see Gallery, layout of HPP Schiffmühle). In the scope of FIThydro, the residual flow HPP is the investigated case study HPP. This HPP has an installed capacity of 0.5 MW and a mean annual output of 1.9 GWh. It operates with a bevel gear bulb turbine.

===The Operator: Limmatkraftwerke AG (LKW)===
LKW produces environmentally friendly and local electricity from four main and two residual flow hydropower plants on river Limmat between Baden and Turgi. The company is owned by the Regionalwerke Holding AG Baden (60%), a local utility company, and the regional power company AEW (40%). The Regionalwerke AG Baden is responsible for the operation of the HPPs and all technical and energy management issues. The administrative and financial management are performed by Axpo AG. The average annual energy output is around 91 GWh. The company fulfills the standards according to ISO 9001 and the production of renewable energy is certified by TÜV SÜD Erzeugung EE.

=Pressures on the water body's ecosystem=
The river Limmat is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon rivers in Europe. The upstream migration of salmons (Salmo salar) in the Rhine catchment became almost impossible due to transverse structures such as hydropower plants. In the past few years a number of HPPs on the Rhine, Aare and Limmat rivers have been equipped with state-of-the-art fish passage facilities for upstream migration. However, downstream migration measures and sediment management strategies have hardly been realized. Furthermore, the Limmat river is highly influenced by HPPs and densely populated areas and considered as a heavily modified water body. The river has a moderate ecological potential. Various measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
All of the existing fish species in the Limmat river (at least 22 species) face potential mortality during their downstream migration, some of which also have difficulties to migrate upstream. Some of the most important species are: Eel (Anguilla anguilla), Brown trout, Common barbel (Barbus barbus), Grayling, Spirlin, Nase, Chub, Bleak.

===Downstream migration===
At the residual flow HPP Schiffmühle, an angled fish guidance structure with horizontal bars, termed Horizontal Bar Rack (HBR), has been implemented in 2013 to shield fish from the turbine intake and guide them into an adjacent bypass and to the tailwater. The rack is positioned parallel to the main flow to have a lateral intake. The HBR has a length of 14.6 m and a spacing of 20 mm between the bars, which are positioned in a vertical angle of 90°. At the end of the rack there is the bypass inlet with two openings in a vertical chamber in different water depths (close to the bottom and close to the surface). From there, a 25 cm diameter pipe bypasses the fish downstream, letting them out at about 0.20 m above the tailwater level. The discharge in the bypass is 170 l/s.

For monitoring downstream migrating fish, 1 PIT-tag antenna has been installed at the bypass pipe inlet.

===Upstream migration===
The residual flow HPP Schiffmühle has a combination of a nature-like and a technical fish pass (vertical slot) for upstream migration. The entrances of the nature-like fish pass and the vertical slot pass are located approx. 36 m and 2 m downstream of the turbine flow outlet, respectively. The technical and the nature-like fish passes merge at an elevation of 336.83 m a.s.l. (see figures in the Gallery). From there on upwards, fish use the nature-like pass. The total discharge in the fishway is 0.5 m3/s.

To monitor upstream migration and fish behavior in the migration facilities, 5 PIT-tag antennas have been installed in the technical vertical slot fish pass and in the nature-like pass.

===E-flow===
The residual flow HPP Schiffmühle supplies up to 14.6 m3/s of turbine water and 0.67 m3/s of the water in the fish passage facilities (upstream and downstream) to the downstream river reach as e-flow. Moreover, during high river discharges, additional water is supplied over the frontal weir at the HPP and over the side weir along the headrace channel to the residual flow reach.

===Sediment management===
An innovative vortex tube for bed load transport connectivity has been installed in 2002 in the headrace channel to guide bed load to the residual flow stretch of the Limmat river during floods. Additionally, sediment can be flushed via the weir flap gate.

=Research objectives and tasks=
The studies at HPP Schiffmühle address various aspects of the upstream and downstream fish passes, downstream habitat and sediment transport. The findings of the studies will have a wide range of applications for other HPPs and will give answers to the fundamental questions on fish behavior at fish passes.
===Research tasks===
The research tasks and field studies conducted at HPP Schiffmühle are:

* Field campaign: hydraulics, habitat, attraction flow and Lateral Line Probe in upstream fish pass
* 3D numerical model of the HPP perimeter
* Fish monitoring
* Bed load monitoring at vortex tube
* Habitat and sediment modelling

=Results=
The flow conditions at the entrance of the nature-like fishway of the residual flow HPP Schiffmühle is more attractive for all monitored fish species than the flow condition at the entrance of the vertical slot fishway close to the draft tube outlet. However, the fish entrance efficiency is higher for the vertical slot fishway. Overall, the passage efficiency of the fish pass system is high (> 80 % for most species monitored), indicating an appropriate design and a good functionality.

Regarding downstream fish migration, velocity measurements and fish monitoring results show that the attraction flow to the bypass of the fish protection and guidance structure (Horizontal Bar Rack-Bypass System) is inefficient and needs to be upgraded and optimized. The results indicate that the design, location and operation of a fish guidance rack-bypass system is of prime importance for a successful implementation and a high guidance efficiency. Using a 3D numerical model, alternative bypass designs in terms of layout and inlet location have been investigated.

=Gallery=
<gallery mode=packed>
Schiffmühle_aerial.png|Aerial overview of Schiffmühle HPP; flow direction from top to bottom
schillmuhle_spillway.jpg|Residual flow HPP (left), flap-gated weir (centre) and headrace channel to the main HPP Schiffmühle (right); view to downstream
schillmuhle_fishway.jpg|Nature-like fishway at Schiffmühle HPP
Layout-Picture_Schiffmühle_CVAW_ETHZ_web-scaled.jpg|Layout of Schiffmühle HPP
schillmuhle_upstream-migration-devices_c_ETHZ_web-scaled.jpg|Overview of fish migration devices at Schiffmühle HPP
schiffmuhle_vertical_slot_fishway.jpg|Vertical slot fishway at Schiffmühle HPP
schiffmuhle_downstream-migration-devices_photo_2.jpg|Schematic of fish migration devices at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_photo_4.jpg|Outlet of sediment vortex tube at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_setup.jpg|Setup of the sediment vortex tube at Schiffmühle HPP
schiffmuhle_Calibration-of-sediment-monitoring-system-for-vortex-tube.jpg|Calibration of the sediment vortex tube monitoring system at Schiffmühle HPP
</gallery>

Schiffmühle test case

2020-05-08T14:05:30Z

Ismailalbayrak: /* Downstream migration */

[[Category:Test cases]]
{{Fact box for Schiffmühle}}
{{Relevant SMTDs for Schiffmühle}}

=Introduction=
The hydropower plant (HPP) Schiffmühle is a run-of-the-river HPP located on the 35 km long stretch of the Limmat river in the communities of Untersiggenthal and Turgi near Baden, some 27 km downstream of Lake Zurich. Between lake Zurich and Schiffmühle there are seven HPPs, namely in flow direction Letten, Höngg , Dietikon, Wettingen, Aue, Oederlin and Kappelerhof. There are three more HPPs between HPP Schiffmühle and the junction with the Aare river, namely Turgi, Gebenstorf and Stroppel. The lowest and highest points of the Limmat river are 330 m and 406 m asl, respectively. The surface area of the whole catchment amounts to 2384 km2, of which 0.7 % are glaciated.

On river Limmat, the mean monthly discharge increases from March to June and then decreases from July to October. The annual discharge in 2015 was 89 m3/s, while the long-term average is 101 m3/s (1951-2015).

=About the hydropower plant=
At Schiffmühle, hydropower is exploited in two run-of-river HPPs, namely the main powerhouse located at the end of a headrace channel on the right shore and the residual flow HPP situated next to a flap gate at the upstream end of the weir on the left shore (see Gallery, layout of HPP Schiffmühle). In the scope of FIThydro, the residual flow HPP is the investigated case study HPP. This HPP has an installed capacity of 0.5 MW and a mean annual output of 1.9 GWh. It operates with a bevel gear bulb turbine.

===The Operator: Limmatkraftwerke AG (LKW)===
LKW produces environmentally friendly and local electricity from four main and two residual flow hydropower plants on river Limmat between Baden and Turgi. The company is owned by the Regionalwerke Holding AG Baden (60%), a local utility company, and the regional power company AEW (40%). The Regionalwerke AG Baden is responsible for the operation of the HPPs and all technical and energy management issues. The administrative and financial management are performed by Axpo AG. The average annual energy output is around 91 GWh. The company fulfills the standards according to ISO 9001 and the production of renewable energy is certified by TÜV SÜD Erzeugung EE.

=Pressures on the water body's ecosystem=
The river Limmat is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon rivers in Europe. The upstream migration of salmons (Salmo salar) in the Rhine catchment became almost impossible due to transverse structures such as hydropower plants. In the past few years a number of HPPs on the Rhine, Aare and Limmat rivers have been equipped with state-of-the-art fish passage facilities for upstream migration. However, downstream migration measures and sediment management strategies have hardly been realized. Furthermore, the Limmat river is highly influenced by HPPs and densely populated areas and considered as a heavily modified water body. The river has a moderate ecological potential. Various measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
All of the existing fish species in the Limmat river (at least 22 species) face potential mortality during their downstream migration, some of which also have difficulties to migrate upstream. Some of the most important species are: Eel (Anguilla anguilla), Brown trout, Common barbel (Barbus barbus), Grayling, Spirlin, Nase, Chub, Bleak.

===Downstream migration===
At the residual flow HPP Schiffmühle, an angled fish guidance structure with horizontal bars, termed Horizontal Bar Rack (HBR), has been implemented in 2013 to shield fish from the turbine intake and guide them into an adjacent bypass and to the tailwater. The rack is positioned parallel to the main flow to have a lateral intake. The HBR has a length of 14.6 m and a spacing of 20 mm between the bars, which are positioned in a vertical angle of 90°. At the end of the rack there is the bypass inlet with two openings in a vertical chamber in different water depths (close to the bottom and close to the surface). From there, a 25 cm diameter pipe bypasses the fish downstream, letting them out at about 0.20 m above the tailwater level. The discharge in the bypass is 170 l/s.

For monitoring downstream migrating fish, 1 PIT-tag antenna has been installed at the bypass pipe inlet.

===Upstream migration===
HPP Schiffmühle has a combination of a nature-like and a technical fish pass (vertical slot) for upstream migration. The entrances of the nature-like fish pass and the vertical slot pass are located approx. 36 m and 2 m downstream of the turbine's suction tube outlet, respectively. The technical and the nature-like fish passes merge at an elevation of 336.83 m a.s.l. (see figures in the Gallery). From there on upwards, fish use the nature-like pass. The total discharge in the fishway is 0.5 m3/s.

To monitor upstream migration and fish behavior in the migration facilities, 5 PIT-tag antennas have been installed in the technical vertical slot fish pass and in the nature-like pass.

===E-flow===
The residual flow HPP Schiffmühle supplies up to 14.6 m3/s of turbine water and 0.67 m3/s of the water in the fish passage facilities (upstream and downstream) to the downstream river reach as e-flow. Moreover, during high river discharges, additional water is supplied over the frontal weir at the HPP and over the side weir along the headrace channel to the residual flow reach.

===Sediment management===
An innovative vortex tube for bed load transport connectivity has been installed in 2002 in the headrace channel to guide bed load to the residual flow stretch of the Limmat river during floods. Additionally, sediment can be flushed via the weir flap gate.

=Research objectives and tasks=
The studies at HPP Schiffmühle address various aspects of the upstream and downstream fish passes, downstream habitat and sediment transport. The findings of the studies will have a wide range of applications for other HPPs and will give answers to the fundamental questions on fish behavior at fish passes.
===Research tasks===
The research tasks and field studies conducted at HPP Schiffmühle are:

* Field campaign: hydraulics, habitat, attraction flow and Lateral Line Probe in upstream fish pass
* 3D numerical model of the HPP perimeter
* Fish monitoring
* Bed load monitoring at vortex tube
* Habitat and sediment modelling

=Results=
The flow conditions at the entrance of the nature-like fishway of the residual flow HPP Schiffmühle is more attractive for all monitored fish species than the flow condition at the entrance of the vertical slot fishway close to the draft tube outlet. However, the fish entrance efficiency is higher for the vertical slot fishway. Overall, the passage efficiency of the fish pass system is high (> 80 % for most species monitored), indicating an appropriate design and a good functionality.

Regarding downstream fish migration, velocity measurements and fish monitoring results show that the attraction flow to the bypass of the fish protection and guidance structure (Horizontal Bar Rack-Bypass System) is inefficient and needs to be upgraded and optimized. The results indicate that the design, location and operation of a fish guidance rack-bypass system is of prime importance for a successful implementation and a high guidance efficiency. Using a 3D numerical model, alternative bypass designs in terms of layout and inlet location have been investigated.

=Gallery=
<gallery mode=packed>
Schiffmühle_aerial.png|Aerial overview of Schiffmühle HPP; flow direction from top to bottom
schillmuhle_spillway.jpg|Residual flow HPP (left), flap-gated weir (centre) and headrace channel to the main HPP Schiffmühle (right); view to downstream
schillmuhle_fishway.jpg|Nature-like fishway at Schiffmühle HPP
Layout-Picture_Schiffmühle_CVAW_ETHZ_web-scaled.jpg|Layout of Schiffmühle HPP
schillmuhle_upstream-migration-devices_c_ETHZ_web-scaled.jpg|Overview of fish migration devices at Schiffmühle HPP
schiffmuhle_vertical_slot_fishway.jpg|Vertical slot fishway at Schiffmühle HPP
schiffmuhle_downstream-migration-devices_photo_2.jpg|Schematic of fish migration devices at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_photo_4.jpg|Outlet of sediment vortex tube at Schiffmühle HPP
schiffmuhle_sediment-management_vortex_tube_setup.jpg|Setup of the sediment vortex tube at Schiffmühle HPP
schiffmuhle_Calibration-of-sediment-monitoring-system-for-vortex-tube.jpg|Calibration of the sediment vortex tube monitoring system at Schiffmühle HPP
</gallery>

Bannwil test case

2020-05-08T13:22:56Z

Ismailalbayrak: /* Results */

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With three bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (''Salmo salar'') rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

===Downstream migration===
There is no specific measures implemented at HPP Bannwil. Fish can pass through the turbines and/or over the weirs when they are in operation. Weir discharge occurs on average (1935-2015) for about 42 days per year.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

The results of the studies on downstream fish migration at HPP Bannwil indicate that no fish injury is expected during fish spillway passage since fish terminal velocity is higher than the weir velocity. However, due to back-roll in the stilling basin of spillway, fish might be exposed to increased predation or strike to baffle blocks. Numerical model results also indicate that hydraulic conditions at potential positions of a fish guidance structure in front of the turbines are unfavorable.

Analysis of the Biological Performance Assessment (BioPA) based on the CFD simulation of the turbines indicate that the average fish friendliness scores of the HPP Bannwil are 9.1 and 8.5 out of 10 at an acclimation depth of 5 m and 10 m, respectively. The former i.e. 5 m is more realistic for the HPP regarding the depth of the river. For an absolute fish survival rating, this factor plays an important role.

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Bannwil test case

2020-05-08T13:20:43Z

Ismailalbayrak: /* Test case topics */

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With three bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (''Salmo salar'') rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

===Downstream migration===
There is no specific measures implemented at HPP Bannwil. Fish can pass through the turbines and/or over the weirs when they are in operation. Weir discharge occurs on average (1935-2015) for about 42 days per year.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Bannwil test case

2020-05-08T13:18:08Z

Ismailalbayrak: /* Pressures on the water body's ecosystem */

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With three bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (''Salmo salar'') rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Bannwil test case

2020-05-08T13:16:49Z

Ismailalbayrak: /* About the hydropower plant */

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With three bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (Salmo salar) rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Bannwil test case

2020-05-08T13:16:01Z

Ismailalbayrak: /* Introduction */

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With thre bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (Salmo salar) rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Bannwil test case

2020-05-08T13:15:41Z

Ismailalbayrak: /* Introduction */

[[Category:Test cases]]
{{Fact box for Bannwil}}
{{Relevant SMTDs for Bannwil}}

=Introduction=
The Bannwil hydropower plant (HPP) is a run-of-the-river HPP on the river Aare located in the community of Bannwil, some 46 km downstream of Lake Biel. There are two upstream HPPs on the Aare river below Lake Biel, HPP Brügg at the lake outflow and HPP Flumenthal about 12 km from Bannwil.

The river Aare is a 291 km long tributary of the Rhine and the longest river within Switzerland. The Aare River passes through three major lakes: Lake of Brienz, Lake of Thun and Lake of Biel.

There are in total 12 HPPs on the Aare river stretch between Lake Biel and the junction with the Rhine river, and two nuclear power plants with water abstraction for cooling.

The altitude of the lowest and highest points of this river reach are ca. 312 m a.s.l. and 429 m a.s.l., respectively. The average altitude of the whole catchment amounts to 1060 m a.s.l. and the whole catchment area is 17687 km2, of which 1.4 % are covered by glaciers. On the river Aare, the mean monthly discharge increases from February to June and then decreases from July to October. The multi-year annual discharge amounts to 268 m3/s. The design discharge of HPP Bannwil of 450 m3/s is exceeded on average for about 42 days a year.

=About the hydropower plant=

The Bannwil weir is located on the right side of the river, while the powerhouse is located on the left side. The reservoir impoundment is about 7 km long. With thre bulb turbines, HPP Bannwil has an installed capacity of 28.5 MW and an average annaul production of 150 GWh. The gross head amounts to 5.5 - 8.5 m, depending on the up- and downstream water levels, with a designed discharge of 450 m3/s.
===The Operator: BKW===
HPP Bannwil is operated by the BKW group. The group plans, builds and operates infrastructure to produce and supply energy to businesses, households and the public sector, and offers digital business models for renewable energies. [https://www.bkw.ch/en/about-us/company/about-us/ Read more.]

=Pressures on the water body's ecosystem=
The river Aare is located in the Rhine river catchment, which was historically one of the most important Atlantic salmon (Salmo salar) rivers in Europe. The upstream migration of salmons in the Rhine catchment became almost impossible after intense hydropower plant constructions, including the Aare river catchment. All of the occurring fish species present in the Aare river (total of 44 fish species) face potentially high mortality during downstream migration or difficulties during upstream migration.

Furthermore, the river Aare is highly influenced by hydropower and considered as a heavily modified water body. Moreover, there are three nuclear power plants on the Aare river, two of them reintroducing the used cooling water, which induces an increase of the river water temperature. The river has a moderate ecological potential. Measures for sediment control, fish migration, flow changes, habitat in-channel and morphology off-channel have been implemented in the water body.

=Test case topics=
===Fish population===
There are a total of 44 fish species in the river Aare, amongst which eel (Anguilla anguilla), brown trout (Salmo trutta), chub (Squalius cephalus), grayling (Tymallus thymallus), spirlin (Alburnus alburnus), and common barbel (Barbus barbus). Salmon is expected to come back in the next 10-20 years after construction and upgrading of fish passes at HPPs on the Rhine river.

===Upstream migration===
The current fish pass is a pool-type design with bottom and top openings. The entrance is located on the left shore shortly downstream of the powerhouse. The bottom slope of the technical fish pass is on average 6 %. Most of the head difference is accomplished in the first half of the fishway consisting of pools placed spirally. The upper part of the fishway consists of a nearly horizontal channel that leads to the exit roughly 100 m upstream of the HPP axis. The mean discharge in the fishway amounts to 350 l/s.

The fish pass needs to be restructured to accommodate larger fish in the near future. Current plans include replacing the lower part with a vertical slot pass and the upper part with a nature like open channel pass.

=Research objectives and tasks=
At Bannwil HPP, downstream fish migration measures are investigated by means of field and CFD studies. The current situation and the efficiency of spill flow or water release as an operational measure at HPP Bannwil are investigated through field monitoring and 3-D numerical modelling in the areas near the powerhouse and weir. Applying this model to different structural and/or operational scenarios gives hints to solutions to improve fish migration at reduced energy losses. Dynamic pressure fluctuations experienced by fish during the turbine and spillway passages are studied at HPP Bannwil using a Barotrauma Detection System (BDS) developed at TUT. Based on the data, a CFD-model will be developed, which can then be used to evaluate the fish passage in order to judge the possibility of adapting the hydropower operation for certain time periods.
===Research tasks===
The research tasks and field studies conducted at HPP Bannwil are:

* Velocity & hydraulic measurements
* 3D turbine & HPP CFD models with Biological Performance Assessment and Barotrauma Detection System
* Fish monitoring; Survey of fish movement using ARIS Sonar and radio telemetry techniques
* Variant Study

=Results=

=Gallery=
<gallery mode=packed>
HPP Bannwil River Aare.jpg|Aerial view of Bannwil HPP; flow direction from top to bottom.
HPP Bannwil River Aare2.jpg|View of Bannwil HPP from downstream [1].
HPP Bannwil River Aare3.jpg|View of Bannwil HPP from downstream [2].
Bannwil Layout.png|Layout of the Bannwil HPP and surrounding area; flow direction from bottom to top.
</gallery>

Template:Fact box for Bannwil

2020-05-08T13:13:56Z

Ismailalbayrak:

{| class="wikitable" style="float:right;width:350px;"
! colspan="2" style="text-align: center;background-color:#2cb4da; color:#ffffff;" | Fact box: Bannwil
|-
| Country
| Switzerland
|-
| River
| Aare
|-
| Operator
| BKW Energie AG
|-
| Capacity
| 28.5 MW
|-
| Head
| 5.5 - 8.5 m
|-
| Inter-annual discharge
| 268 m3/s
|-
| Turbine(s)
| 3 Bulb turbines
|-
| Detailed report
|[[:file:testcase_presentation_Bannwil.pdf|Click for pdf]]
|}