de Bie, Jasper

Kemp, Paul

English

ScholarWorks@UMass Amherst

University of Massachusetts AmherstScholarWorks@UMass AmherstInternational Conference on Engineering andEcohydrology for Fish PassageInternational Conference on Engineering andEcohydrology for Fish Passage 2016Jun 22nd, 9:15 AM - 9:30 AMFish Passage Studies IV: Horizontal and VerticalScreens: Efficacy in Guiding Fish SchoolsJasper de BieInternational Centre for Ecohydraulics ResearchPaul KempInternational Centre for Ecohydraulics ResearchFollow this and additional works at: https://scholarworks.umass.edu/fishpassage_conferenceThis Event is brought to you for free and open access by the Fish Passage Community at UMass Amherst at ScholarWorks@UMass Amherst. It hasbeen accepted for inclusion in International Conference on Engineering and Ecohydrology for Fish Passage by an authorized administrator ofScholarWorks@UMass Amherst. For more information, please contact scholarworks@library.umass.edu.de Bie, Jasper and Kemp, Paul, "Fish Passage Studies IV: Horizontal and Vertical Screens: Efficacy in Guiding Fish Schools" (2016).International Conference on Engineering and Ecohydrology for Fish Passage. 15.https://scholarworks.umass.edu/fishpassage_conference/2016/June22/15Horizontal & vertical screens:efficacy in guiding fish schoolsJasper de Bie & Paul Kemp22 June 2016Outline• Background• Aim and objectives• Methodology• Results• ConclusionsBackground• Variety of screening devices to block DS fish from entering harmful areas / guide them to safe bypass.– Behavioural / mechanical– Local changes in hydraulics (e.g., turbulent high flows)– Possible delay etc.• Traditionally,  bar racks/ trash racks/ wedge-wire screens have vertically oriented barsBackground• It can be hypothesized that horizontal orientation of bars can be more effective:1. Aspect ratio of most fish implies that they are blocked earlier by horizontal bars2. Fish are better able to free themselves when impingedAim & objectivesInvestigate effect of wedge-wire screens (horz. & vert.) on behaviour and passage of fish schools1. Determine hydraulic differences between screens for different flows2. Determine behavioural response to screens3. Link hydraulics and behaviour to provide insight into efficiency of screensMethodology3 mm6 mmAB C• 30°angle to the flow • Low (Ua~ 17 cm/s) and High (Ua~35 cm/s) discharge• ADV measurements above channel floor• 5 chub (Squalius cephalus) released per 2hr trial & record DS movements80 100 120 140 160 180 200 220 240 260 280 30000.10.20.30.40.50.6Longitudinal distance (cm)Velocity (m s-1 )Mean velocity  LH LV HH HVGradient along screen(cm s-1 m-1)LH: 1.6LV: 2.4HH: 5.2HV: 6.0  80 100 120 140 160 180 200 220 240 260 280 30000.050.10.150.20.250.30.350.40.450.5Longitudinal distance (cm)Velocity (m s-1 )Cross-sweeping velocity  LH LV HH HV80 100 120 140 160 180 200 220 240 260 280 30000.050.10.150.20.25Longitudinal distance (cm)Velocity (m s-1 )Escape velocity  LH LV HH HV• Both cross-sweeping and escape velocity increase toward bypass• Horizontal screens generally lower components compared to vertical screensBehavioural results• School cohesion was weak– Both approaches and passage for different group sizes• Passage success > 80%• Screen passage efficiency:– Total number of fish that passed along the screen as percentage of number of approaches at the screen, per replicate• Number of fish that passed along the screen• Distance travelled before upstream retreatConclusions• Vertical screens divert more water --> higher flow gradient towards bypass• Horizontal screens must have lower head losses – useful from HP perspective• Both flow and screen affect passage efficiency• Horizontal screens see more passed fish• Distance along screen influenced by discharge• Horizontal screens offer benefits for guiding fish!Thank you Jdb1u11@soton.ac.ukJdeBie.uk@gmail.com

Fish Passage Studies IV: Horizontal and Vertical Screens: Efficacy in Guiding Fish Schools

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Fish Passage Studies IV: Horizontal and Vertical Screens: Efficacy in Guiding Fish Schools

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