Blar i NTNU Open på forfatter "Alfredsen, Knut"
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Can model-based data products replace gauge data as input to the hydrological model?
Sivasubramaniam, Kuganesan; Alfredsen, Knut; Rinde, Trond; Sæther, Bjørn (Journal article; Peer reviewed, 2020)Hydrological models require accurate and representative meteorological inputs for better prediction of discharge and hence, the efficient management of water resources. Numerical weather prediction model-based reanalysis ... -
Changes in short term river flow regulation and hydropeaking in Nordic rivers
Ashraf, Faisal; Haghighi, Ali Torabi; Riml, Joakim; Alfredsen, Knut; Koskela, Jarkko; Kløve, Bjørn; Marttila, Hannu (Journal article; Peer reviewed, 2018)Quantifying short-term changes in river flow is important in understanding the environmental impacts of hydropower generation. Energy markets can change rapidly and energy demand fluctuates at sub-daily scales, which may ... -
Classification of hydropeaking impacts on Atlantic salmon populations in regulated rivers
Bakken, Tor Haakon; Harby, Atle; Forseth, Torbjørn; Ugedal, Ola; Sauterleute, Julian Friedrich; Halleraker, Jo Halvard; Alfredsen, Knut (Peer reviewed; Journal article, 2021)This article proposes and demonstrates a new classification system of fish population level effects of hydropeaking operations in rivers. The classification of impacts is developed along two axes; first, the hydromorphological ... -
Climate change and hydrological analysis of Tekeze river basin Ethiopia: implication for potential hydropower production
Adera, Abebe Girmay; Alfredsen, Knut (Peer reviewed; Journal article, 2019)Climate change is expected to intensify the hydropower production in East Africa. This research investigates the runoff and energy production in the current and future climate for the Tekeze hydropower plant located in the ... -
Climate Change and Increased Irrigation Demands: What Is Left for Hydropower Generation? Results from Two Semi-Arid Basins
Bakken, Tor Haakon; Almestad, C; Rugelbak, JM; Escobar, M; Micko, S; Alfredsen, Knut (Journal article; Peer reviewed, 2016-03-14)In this study, we have modelled the effect of climate change and increased irrigation withdrawals on the available water for hydropower production in two semi-arid river basins, i.e., Kizilirmak (Turkey) and Devoll (Albania), ... -
Climate Change Assessments for the Gaula River
Naher, Kamrun (Master thesis, 2019)The effects of climate change were assessed for Gaula, south of Trondheim in Norway as a wetting winter and drying summer are predicted to occur in the future. The research was done in six steps to find the effect of a ... -
Climate change impacts Norwegian hydropower systems
Otel, Andreea-Cristina (Master thesis, 2016)Climate change impacts hydropower sytems in Norway -
Combining green LiDAR bathymetry, aerial images and telemetry data to derive mesoscale habitat characteristics for European grayling and brown trout in a Norwegian river
Sundt, Håkon; Alfredsen, Knut; Museth, Jon; Forseth, Torbjørn (Peer reviewed; Journal article, 2021)While many studies provide microscale relationships between fish and habitat characteristics, studies covering longer river reaches are scarce. Modern remote sensing techniques may enable new and effective ways of mapping ... -
Comparative evaluation of performances of different conceptualisations of distributed HBV runoff response routines for prediction of hourly streamflow in boreal mountainous catchments
Hailegeorgis, Teklu Tesfaye; Alfredsen, Knut (Journal article; Peer reviewed, 2015)Unidentifiability and equifinality of parameters pose challenges to calibration and prediction by conceptual precipitation-runoff models. Evaluation of prediction performances of parametrical parsimonious and more complex ... -
Comparison between the Green and the Red LiDAR terrain models in flood inundation estimations
Awadallah, Mahmoud Omer Mahmoud (Master thesis, 2021)LiDAR data has revolutionized the availability of digital elevation models, basis to generate flood inundations. Red LiDAR is the common methodology for scanning terrain, but for hydraulic applications, it cannot penetrate ... -
Comparison between Topographic and Bathymetric LiDAR Terrain Models in Flood Inundation Estimations
Awadallah, Mahmoud Omer Mahmoud; Juarez Gomez, Ana; Alfredsen, Knut (Peer reviewed; Journal article, 2022)Remotely sensed LiDAR data has allowed for more accurate flood map generation through hydraulic simulations. Topographic and bathymetric LiDARs are the two types of LiDAR used, of which the former cannot penetrate water ... -
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 ... -
Detection and apparent survival of PIT-tagged stream fish in winter
Weber, Christine; Scheuber, Hannes; Nilsson, Christer; Alfredsen, Knut (Journal article; Peer reviewed, 2016)Environmental fluctuations exert strong control on behavior, survival, and fitness of stream biota. Technical improvements increasingly allow for tracking the response of large numbers of individuals to environmental ... -
Deteksjon av fremmedvann i separatsystemer med isotoper
Solberg, Lars (Master thesis, 2017)Utgangspunktet for denne oppgaven er å definere egnetheten til en hittil lite utprøvd metode for lekkasjesøking i separate spillvannsledninger. Rent praktisk tar metoden utgangspunkt i å benytte stabile isotoper i ulike ... -
Developing semi-automated GIS methods for indicating downstream flood damage potential of critical points
Skurdal, Torgeir (Master thesis, 2022)Overvannsflom er allerede et stort problem som påvirker mange Norske kommuner, og prognoser spår økende temperatur, årlig nedbør og ekstremvær gjør at flom vil fortsette å være problematisk i overskuelig fremtid. Regionale ... -
Development of an inflow-controlled environmental flow regime for a Norwegian river
Alfredsen, Knut; Harby, Atle; Linnansaari, Tommi; Ugedal, O (Journal article, 2012)Hydropower produces 99% of the electricity in Norway, and a large number of rivers are regulated. Currently, static minimum flow regimes are used as a mitigation measure for most of these developments, usually having fixed ... -
Distributed Hydrological Modelling of Lærdal Catchment to Investage Changes in Flow Pattern
Yancy, Tamba C'Diem (Master thesis, 2022)ABSTRAKT Estimering av strømning til uregulerte sideelver er svært viktig i regulerte bassenger. Bruken av distribuerte hydrologiske modeller er betydelig i de fleste tilfeller når man prøver å hente ut tilsig før regulering ... -
Drone surveying of volumetric ice growth in a steep river.
Rødtang, Einar Albert; Alfredsen, Knut; Juarez, Ana (Journal article; Peer reviewed, 2021) -
Ecohydraulic Modelling to Support Fish Habitat Restoration Measures
Adeva Bustos, Ana; Alfredsen, Knut; Fjeldstad, Hans-Petter; Ottoson, Kenneth (Journal article; Peer reviewed, 2019)Despite that hydromorphological restoration projects have been implemented since the 1940s, the key to improve the effectiveness of future restoration measures remains a challenge. This is in part related to the lack of ... -
Effektivitet og kost-nytte forhold av fysiske miljøtiltak i vassdrag
Pulg, Ulrich; Stranzl, Sebastian Franz; Espedal, Espen Olsen; Gabrielsen, Sven Erik; Postler, Christoph; Ugedal, Ola; Jensås, Jan Gunnar; Bremset, Gunnbjørn; Fjeldstad, Hans-Petter; Alfredsen, Knut (LFI - Laboratorium for ferskvannsøkologi og innlandsfiske;, Research report, 2020)Det er økt fokus på bedring av fysiske miljøforhold i vassdrag, og med dette har behovet for å kunne vurdere kostnader og nytte ved slike tiltak økt. Prinsippet om «positiv kost-nytte» legges eksempelvis til grunn ved ...