Sökning: "fish-ladder"

Visar resultat 1 - 5 av 14 uppsatser innehållade ordet fish-ladder.

  1. 1. Byggandet av fiskvägar och möjligheten för samordning med betongunderhåll

    Kandidat-uppsats,

    Författare :Lucas Johansson; [2022]
    Nyckelord :Hydropower; fish-ladder; concrete maintenance; bundling; cost; Vattenkraftverk; fisktrappa; fiskväg; kostnad; nationell plan för omprövning;

    Sammanfattning : Många av Sveriges vattenkraftverk drivs med gamla tillstånd. Detta har letttill att regeringen tvingat fram en omprövning av alla elproducerandevattenkraftverk mot miljöbalken och moderna miljövillkor. LÄS MER

  3. 2. Convolutional neural network based object detection in a fish ladder : Positional and class imbalance problems using YOLOv3

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Patrik Ekman; [2021]
    Nyckelord :Object detection; Computer vision; Fish ladder; Imbalance problems; Imbalanced data; YOLO; Convolutional Neural Network; Deep learning; Objektdetektering; Datorseende; Fisktrappa; Obalanser; Obalanserad data; YOLO; Convolutional Neural Network; Djupinl¨arning;

    Sammanfattning : Hydropower plants create blockages in fish migration routes. Fish ladders can serve as alternative routes but are complex to install and follow up to help adapt and develop them further. In this study, computer vision tools are considered in this regard. LÄS MER

  4. 3. Study of a vertical slot fish ladder : Evaluation of flow dynamics through a standardized bypass and the effect of predesigned roughness elements

    Magister-uppsats, Högskolan i Gävle/Avdelningen för byggnadsteknik, energisystem och miljövetenskap

    Författare :Iñigo Revilla; Laia Pons; [2020]
    Nyckelord :Vertical slot fishway; roughness element; pattern; slope; velocity; turbulence; Fluent;

    Sammanfattning : Migrating freshwater fish population has been significantly declined, mostly by the obstruction of their migratory routes by hydropower dams. To diminish such impacts, fish ladders have been developed to facilitate the passage of migrating fish. LÄS MER

  5. 4. Downstream migration and survival of Atlantic salmon (Salmo salar L.) kelts and fallbacks when passing a hydropower plant

    Master-uppsats, SLU/Dept. of Wildlife, Fish and Environmental Studies

    Författare :Frans Byström; [2020]
    Nyckelord :migration; kelt; iteroparous; anthropogenic obstacle; survival; turbine passage;

    Sammanfattning : Repeat spawners of Atlantic salmon may be of great importance for population stability, the return spawners can significantly contribute to recruitment of juveniles. To have a significant proportion of repeat spawners in the population, it is necessary that salmons can successfully migrate back to the sea after spawning upriver. LÄS MER

  7. 5. Sexual dimorphism in the migratory dynamics of a land-locked population of brown trout (Salmo trutta) in central Sweden : a study at three temporal scales

    Master-uppsats, SLU/Dept. of Wildlife, Fish and Environmental Studies

    Författare :Carl Vigren; [2018]
    Nyckelord :trout; salmonid; salmo; trutta; migration; upstream; Storsjon; Storsjön; Damman; Dammån; regulated; fish ladder; behaviour; protandry;

    Sammanfattning : In this study I use a 56 years long dataset to study the migratory behaviours of a land-locked population of Brown trout (Salmo trutta) in the river Dammån, positioned in central Sweden. I found that there was a mean female-to-male sex ratio in the spawning-run of approximately 2.31 with an average 50% run date on the 29th of July. LÄS MER