Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2022
Forfattere
Randika K. Makumbura Miyuru Gunathilake Jayanga T. Samarasinghe Remegio Confesor Nitin Muttil Upaka RathnayakeSammendrag
Hydrologic models are indispensable tools for water resource planning and management. Accurate model predictions are critical for better water resource development and management decisions. Single-site model calibration and calibrating a watershed model at the watershed outlet are commonly adopted strategies. In the present study, for the first time, a multi-site calibration for the Soil and Water Assessment Tool (SWAT) in the Kelani River Basin with a catchment area of about 2340 km2 was carried out. The SWAT model was calibrated at five streamflow gauging stations, Deraniyagala, Kithulgala, Holombuwa, Glencourse, and Hanwella, with drainage areas of 183, 383, 155, 1463, and 1782 km2, respectively, using three distinct calibration strategies. These strategies were, utilizing (1) data from downstream and (2) data from upstream, both categorized here as single-site calibration, and (3) data from downstream and upstream (multi-site calibration). Considering the performance of the model during the calibration period, which was examined using the statistical indices R2 and NSE, the model performance at Holombuwa was upgraded from “good” to “very good” with the multi-site calibration technique. Simultaneously, the PBIAS at Hanwella and Kithulgala improved from “unsatisfactory” to “satisfactory” and “satisfactory” to “good” model performance, while the RSR improved from “good” to “very good” model performance at Deraniyagala, indicating the innovative multi-site calibration approach demonstrated a significant improvement in the results. Hence, this study will provide valuable insights for hydrological modelers to determine the most appropriate calibration strategy for their large-scale watersheds, considering the spatial variation of the watershed characteristics, thereby reducing the uncertainty in hydrologic predictions.
Forfattere
Seyedbehnam Hashemi Linn Solli Roald Aasen Jacob Joseph Lamb Svein Jarle Horn Kristian Myklebust LienSammendrag
Det er ikke registrert sammendrag
Sammendrag
Trender i næringsstoff, partikler, klorofyll a og organisk materiale er undersøkt i elvene Hæra og Rakkestadelva, og innsjøene Isesjø, Lundebyvannet, Tunevannet, Lyseren, Ertevatnet og Skinnerflo. Det ble ikke funnet statistisk signifikante trender i elvene. I innsjøene ble det funnet nedgang i totalfosfor og klorofyll a i Lundebyvannet (2000-2021) og klorofyll a i Isesjø (2000-2021). I Lyseren økte konsentrasjonen av totalfosfor (1983 -2021), og i Skinnerflo økte konsentrasjonen av klorofyll a (2011-2021). Det var høye konsentrasjoner av tarmbakterien E. coli særlig i Hæra, og kilder til forurensingen bør identifiseres. Det anbefales en fortsatt høy innsats for miljøtiltak i disse vannforekomstene i Vannområde Glomma Sør.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
This paper presents results from a container experiment and a real-scale study in road environments for evaluating the performance of soil mixtures and herbaceous perennials for use in rain gardens. The container experiment included 12 soil mixtures and 4 perennial species. The plants were exposed to three flooding events and one drought period, and their overall vitality was recorded after the floodings. The containers were stored outdoors the following winter and plant survival was observed in spring. Amsonia orientalis did not survive the winter after being exposed to flooding in the growing season and was replaced by Hosta ‘Francee’ in the real-scale study, which was established in Drammen (Norway) in a soil mixture based on optimisation of the best mixtures in the container experiment. Luzula sylvatica performed well in the container study and survived the winter; however, in the field study, individuals of this species that were located close to the road died due to de-icing salt. Eurybia divaricata showed some mortality in both studies, and total mortality occurred in individuals that were close to the road, due to de-icing salt. Hemerocallis cvv. performed well in both experiments and appeared to be useful in all rain garden positions in the cold climate road environment. H. ‘Francee’ developed well in the road environment, except when exposed to splashes of road water. The study highlights considerable differences between species’ adaption to roadside rain gardens in cold climates, and the need for further field investigations.
Sammendrag
NIBIO og Faun har på oppdrag for Statsforvalteren i Agder gjennomført biologiske undersøkelser i nedre deler av Gjerstadvassdraget for å vurdere forsuringstilstanden. Tre av fem bekker havnet i moderat tilstand for forsuring. Begroingsalgene viste moderat tilstand for forsuring i to av fem bekker. Bunndyrprøvene indikerte god eller bedre tilstand for både forsuring og eutrofiering i fire av fem bekker. Vårprøvene i Espevikbekken indikerte at det oppstår forsuringshendelser på våren. Fiskeundersøkelsene viste gode tettheter av både årsyngel og eldre ungfisk i begge bekkene som ble undersøkt, tilsvarende svært god økologisk tilstand. Prøver av krepsdyr i Holtefjorden og Vasstøvannet indikerte god tilstand.
Sammendrag
Avrenning av nitrogen fra sprengstein gir forhøyede konsentrasjoner av nitrat og ammonium i vassdrag. Avhengig av deponert volum og type masser kan det skje avrenning av store mengder nitrogen, i størrelsesorden 10-70 gram nitrogen per anbrakt kubikkmeter stein. For vassdrag kan tilstanden for nitrogen midlertidig endres fra «svært god» til «svært dårlig». Det er behov for økt kunnskap om midlertidige og varige økologiske effekter av økte tilførsler av nitrogen, særlig i innsjøer og brakkvann. Konsentrasjoner og avrenningsforløp ved utvasking må klarlegges. Etablering av effektive rensetiltak for fjerning av nitrogen i avrenning fra sprengstein og tunnelarbeid har blitt vurdert som vanskelig, og har ikke blitt prøvd ut. Sammenstillingen gir en oversikt over mulige tiltak for fjerning av nitrogen fra anleggsskapt avrenning.
Forfattere
Stepan Marval Petr Fučík Natalja Čerkasova Christoph Schürz Michael Strauch Felix Witing Mikołaj Piniewski Svajunas Plunge Csilla Farkas Sinja Weiland Dominika Krzeminska Tatenda LemannSammendrag
This report introduces a framework and scale specific guidelines for the parameterization of Natural/Small Water Retention Measures (NSWRM) in modelling approaches. More specifically, it provides a detailed translation of NSWRM into parameters and design approaches for the application in the SWAT+ (catchment scale) and SWAP (field-scale) models, which were selected as the main modelling tools in the OPTAIN project. This document can also be considered as an extension of the well-known Conservation Practice Modelling Guide for SWAT and APEX (Waidler et al., 2011), which is frequently used by the SWAT modelling community for testing the effectiveness of conservation practices. However, besides of conservation practices, the report focuses mainly on NSWRMs, and how they can be implemented in SWAT+, the new and restructured version of SWAT. Analogously, the NSWRM parameters are also described for the SWAP model, which is addressing the field-scale. Compared to previous NSWRM modelling approaches, this methodology enables the setting of NSWRM parameters in the two selected models to improve the description of the related hydrological and hydrochemical processes.