Blar i USN Open Archive på forfatter "Alfredsen, Knut"
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Be cool: hydro-physical changes and fish responses in winter in hydropower-regulated northern streams
Heggenes, Jan; Alfredsen, Knut; Adeva Bustos, Ana; Huusko, Ari (Research report, 2016-06-21)In the seasonal climates of northern Europe and North America, winter is considered a particularly ecologically challenging season for aquatic organisms in natural streams. They experience reduced flow and freezing in ... -
A Conflict between Traditional Flood Measures and Maintaining River Ecosystems? A Case Study Based Upon the River Lærdal, Norway
Juarez, Ana; Alfredsen, Knut; Stickler, Morten; Adeva Bustos, Ana; Suarez, Rodrigo; Seguin Garcia, Sonia; Hansen, Bendik Kristoffer Torp (Peer reviewed; Journal article, 2021)Floods are among the most damaging of natural disasters, and flood events are expected to increase in magnitude and frequency with the effects of climate change and changes in land use. As a consequence, much focus has ... -
Hydropower‐driven thermal changes, biological responses and mitigating measures in northern river systems
Heggenes, Jan; Stickler, Morten; Alfredsen, Knut; Brittain, John Edward; Adeva Bustos, Ana; Huusko, Ari (Peer reviewed; Journal article, 2021)Water temperatures control life histories and diversity of aquatic species. Hydropower regulation, particularly in high head systems, alters natural water temperature regimes, which may have profound and long‐term impacts ... -
Identification of salmon population bottlenecks from low flows in a hydro-regulated river
Adeva Bustos, Ana; Hedger, Richard David; Fjeldstad, Hans-Petter; Stickler, Morten; Alfredsen, Knut (Journal article; Peer reviewed, 2019)Flow regime alterations from hydropower regulation may impact fish populations. Impacts can be characterized using methods for mapping bottlenecks for different species life stages. Improving the understanding of such ... -
Quantitative Evaluation of Bathymetric LiDAR Sensors and Acquisition Approaches in Lærdal River in Norway
Awadallah, Mahmoud Omer Mahmoud; Malmquist, Christian; Stickler, Morten; Alfredsen, Knut (Peer reviewed; Journal article, 2023)The development of bathymetric LiDAR technology has contributed significantly to both the quality and quantity of river bathymetry data. Although several bathymetric LiDAR sensors are available today, studies that evaluate ... -
Stay cool : temperature changes and biological responses in hydropower-regulated northern stream systems
Heggenes, Jan; Alfredsen, Knut; Brittain, John E.; Adeva Bustos, Ana; Huusko, Ari; Stickler, Morten (Publication series from University College of Southeast Norway;21, Research report, 2018-01-17)In the seasonal climates of northern Europe and North America, water temperature variations are ecologically challenging for aquatic organisms in natural streams. In winter, low water temperature and ice conditions becall ...