NVE Brage (Norges vassdrags- og energidirektorat)
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Twenty-three unsolved problems in hydrology (UPH) – a community perspective
Full text linkThis paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come
Temarapport om værradarer
Full text linkDenne temarapporten er en del av NVEs forslag til en nasjonal ramme for vindkraft. Rapporten inneholder en gjennomgang av hvordan vindkraftverk kan påvirke værradarene til Meteorologisk Institut
Temarapport om klimaavtrykk og livssyklusanalyser
Full text linkRapporten er en del av NVEs forslag til en nasjonal ramme for vindkraft og presenterer kunnskapsgrunnlaget om klimaavtrykk og livssyklusanalyser for vindkraf
Glaciological investigations in Norway 2018
Full text linkResults of glaciological investigations performed at Norwegian glaciers in 2018 are presented in this report. The main part concerns mass balance investigations. Results from investigations of glacier length changes are discussed in a separate chapter
Aktsomhetskart for løsmasseskred på nedbørfeltnivå for jordskredvarsling
Full text linkA national “susceptibility map for landslides in soils at catchment level” was prepared, to be used in the landslide forecasting and warning service at NVE. The map was elaborated by combining five regional susceptibility assessments and maps carried out between 2013 and 2017 in five regions. This report presents the map and summarize the data and methods used to perform the regional analyses. The document also shows how the map is daily combined with the landslide thresholds, to prepare new national thresholds that take into account the landslide spatial probabilit
SenDiT: The Sentinel-2 Displacement Toolbox with Application to Glacier Surface Velocities
Full text linkSatellite imagery represents a unique opportunity to quantify the spatial and temporal changes of glaciers world-wide. Glacier velocity has been measured from repeat satellite scenes for decades now, yet a range of satellite missions, feature tracking programs, and user approaches have made it a laborious task. To date, there has been no tool developed that would allow a user to obtain displacement maps of any specified glacier simply by establishing the key temporal, spatial and feature tracking parameters. This work presents the application and development of a unique, semi-automatic, open-source, flexible processing toolbox for the retrieval of displacement maps with a focus on obtaining glacier surface velocities. SenDiT combines the download, pre-processing, feature tracking, and postprocessing of the highest resolution Sentinel-2A and Sentinel-2B satellite images into a semi-automatic toolbox, leaving a user with a set of rasterized and georeferenced glacier flow magnitude and direction maps for their further analyses. The solution is freely available and is tailored so that non-glaciologists and people with limited geographic information system (GIS) knowledge can also benefit from it. The system can be used to provide both regional and global sets of ice velocities. The system was tested and applied on a range of glaciers in mainland Norway, Iceland, Greenland and New Zealand. It was also tested on areas of stable terrain in Libya and Australia, where sources of error involved in the feature tracking using Sentinel-2 imagery are thoroughly described and quantified
Glacier velocity data. version 1.0
No full textGlacier surface velocity data for selected glaciers in mainland Norway for the following pairs:
22.08.2016-26.09.2017 - Engabreen
27.08.2017-16.09.2017 - Nigardsbreen
23.07.2016-11.09.2016 - Tunsbergdalsbreen
22.08.2017-18.07.2018 - Rembedalskåka
Sentinel-2A and Sentinel-2B imagery were used for establishing pairs for feature tracking.
The TN toolbox that incorporates IMCORR feature tracking software was used to calculate displacement fields.
Resulting displacement fields were manually filtered taking into account expected magnitude and direction of movement
Naturfareforum : årsrapport 2018
Full text linkI denne rapporten er aktivitetene og ressursbruken i Naturfareforum 2018 oppsummert
Predicting hourly flows at ungauged small rural catchments using a parsimonious hydrological model
Full text linkStreamflow data is important for studies of water resources and flood management, but an inherent problem is that many catchments of interest are ungauged. The lack of data is particularly the case for small catchments, where flow data with high temporal resolution is needed. This paper presents an analysis of regionalizing parameters of the Distance Distribution Dynamics (DDD) rainfall-runoff model for predicting hourly flows at small-ungauged rural catchments. The performance of the model with hourly time resolution has been evaluated (calibrated and validated) for 41 small gauged catchments in Norway (areas from 1 km2–50 km2). The model parameters needing regionalization have been regionalized using three different methods: multiple regression, physical similarity (single-donor and pooling-group based methods), and a combination of the two methods. Seven independent catchments, which are not used in the evaluation, are used for validation of the regionalization methods. All the three methods (the multiple regression, pooling-group, and combined methods) perform satisfactorily (0.5 ≤ KGE < 0.75). The combined method (which combines multiple regression and pooling-group) performed slightly better than the other methods. Some model parameters, namely those describing recession characteristics, estimated by the regionalization methods, appear to be a better choice than those estimated locally from short period of hydro-meteorological data for some test catchments. The single-donor method did not perform satisfactorily. The satisfactory performance of the combined method shows that regionalization of DDD model parameters is possible by combining multiple regression and physical similarity methods
Årsaker til driftsstans i småkraftverk
Full text linkEn spørreundersøkelse rettet seg mot 256 små vannkraftverk for å dokumentere årsakene til driftsstans i kraftverkene. Kun 59 besvarte undersøkelsen på en slik måte at dataene kunne benyttes i analysene. Det var ingen signifikant forskjell i antall stans mellom de som svarte og de som unnlot å besvare spørsmålene. Undersøkelsen viste at vannføring, distribusjonsnettet og driftsforstyrrelser hver for seg var årsaker til stans i over 85 % av kraftverkene. I alt bidro de til 97 % av alle rapporterte stans. Vi kunne ikke påvise forskjell i årsakene til stans i kraftverk med konsesjonsvilkår om jevn drift og kraftverk uten slik restriksjon