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.
2007
Sammendrag
Rapporten er trykket på russisk
Sammendrag
Leakage of tributyltin (TBT) to coastal environment is documented globally and represents environmental hazards because of long half lives in anaerobic environment and accumulation in biota. Concentrations below 1 ng/l influence marine organisms. Hence, pollution control authorities request abatements to mitigate toxic concentration levels. Dredging of contaminated sediments is one abatement strategy, but this approach requires safe landfill repositories. An alternative strategy is to cover contaminated sea bottom areas by cap layers of favourable composition and thereby reduce TBT exposure to the environment. Both abatement strategies require understanding of chemical and physical processes involved at the pore scale and at the field scale. In the present study pore scale processes are investigated by laboratory experiments on dredged sediments from contaminated sea bottom and integrated to field scale by numerical simulations. The distribution of TBT between solid and water phase is a function of several parameters viz texture; composition of clay minerals; content of organic matter; pH; and salinity in the pore water. The influences of these parameters on the mobility of TBT in sediments are studied with emphasize on variable salinity flux through the porous media. In our data the mobility of TBT increases as a function of decreasing salinity. Long term leakage of TBT is simulated in a typified near shore landfill with initial marine salt water concentration in the pore water. Initial TBT concentration in pore water is estimated to 30 ng/l, which is corresponding to a chemical equilibrium of 1 mg/kg of TBT in the sediments. Because sorption of TBT varies as a function of salinity, the transport of TBT has to be coupled to concentration of NaCl in the pore water. The pore water flow depends not only on the relation between infiltration of meteoric water and permeability of the sediments, but also on the concentration of NaCl, thus Darcy law has to be coupled to transport of NaCl. In this way transport of TBT require a coupling of three types of physics. First is Darcy pore water flow coupled to concentration of NaCl, and then concentration of NaCl is coupled to desorption of TBT.
Forfattere
Nils-Otto KitterødSammendrag
Normal snøsmelting om våren skjer ved delvis smelting om dagen med påfølgende innfrysing om natten. Slike gjentagende smelte- og fryseprosesser kan resultere i mer eller mindre sammenhengende islag under snødekket. Et slikt islag reduserer infiltrasjonskapasiteten i jorda og er årsaken til dannelsen av overflatedammer i forsenkninger i åpent terreng eller på dyrka mark. Når telen går, kan det oppstå situasjoner med svært høye infiltrasjonshastigheter. Dette representerer en forurensningsrisiko dersom vannet i dammene er kontaminert. Med normale infiltrasjonshastigheter vil som regel fysiske, kjemiske og biologiske prosesser i jorda holde forurensningen tilbake og bryte ned mesteparten før det når grunnvannet. Lave temperaturer i infiltrasjonsvannet gjør at nedbrytningsprosesser i jorda går langsommere enn normalt. Kombinert med høye infiltrasjonshastigheter, vil risikoen øke for at grunnvann og nærliggende vassdrag blir forurenset.
Forfattere
M.B. Farmani H. Keers Nils-Otto KitterødSammendrag
Cross-well ground penetrating radar (GPR) data sets were collected in the vadose zone of an ice-contact delta near Oslo"s Gardermoen Airport (Norway) before, during, and after snowmelt in 2005. The observed travel times were inverted using curved-ray travel time tomography. The tomograms are in good agreement with the local geologic structure of the delta. The tomographic results were confirmed independently by surface GPR reflection data and x-ray images of core samples. In addition to structure, the GPR tomograms also show a strong time dependency due to the snowmelt. The time-lapse tomograms were used to estimate volumetric soil water content using Topp"s equation. The volumetric soil water content was also observed independently by using a neutron meter. Comparison of these two methods revealed a strong irregular wetting process during the snowmelt. This was interpreted to be due to soil heterogeneity as well as a heterogeneous infiltration rate. The geologic structure and water content estimates obtained from the GPR tomography can be used in forward and inverse flow modeling. Finally, the water balance in the vadose zone was calculated using snow accumulation data, precipitation data, porosity estimates, and observed changes in the groundwater table. The amount of water stored in the vadose zone obtained from the water balance is consistent with the amount estimated using GPR tomography. Alternatively, the change in water storage in the vadose zone can be estimated using GPR tomography. This may then permit estimates of evapotranspiration to be made, provided other components of the water balance are known.
Forfattere
Anne-Grete Buseth BlankenbergSammendrag
Gis i avrenning er et verktøy som beregner næringsavrenning og erosjon fra landbruksområder. Våtmarker/fangdammer og vegetasjonssoner er eksempler på to tiltak som reduserer N, P og erosjon fra landbruksområder til resipienten.
Forfattere
Anne-Grete Buseth Blankenberg Nils-Otto Kitterød Lillian Øygarden Marianne Bechmann Johannes Deelstra Hans Olav Eggestad Heidi Anette GrønstenSammendrag
CLIMATE: Adapating to extreme Weather in municipalities: what, how and why er et instituttprogrammet som går fra 2006-2010. Det er finansiert av Norges Forskningsråd. Bioforsk Jord og miljø skal kartlegge hvordan ekstremvær påvirker prosesser som kan føre til økt erosjon og avrenning av næringssalter som kan gi økt eutrofiering i våre ferskvannsresipienter. CICERO - Senter for klimaforskning, har koordineringsansvar for prosjektet som er et samarbeid mellom instituttene i Miljøalliansen; NIBR, NIKU, NILU, NINA, NIVA og Bioforsk Jord og miljø. Formålet med prosjektet er å øke forståelsen av og å gjelpe kommunene med å håndtere utfordringer de vil stå over for ved ekstremvær.
Forfattere
Anne-Grete Buseth BlankenbergSammendrag
In September 2000 EU agreed to implement the WFD. This led to some new perspectives in Norwegian administration. The areas of activity are watercourse/river systems, groundwater and sea-areas extending to one nautical mile outside the baseline. WFD are considered as a minimum requirement and every country are free to introduce more strict rules. The ministry of Environment are responsible for the coordination of the implementation of the Water Framework Directive in Norway. The government has delegated the responsibility to The Regional Commissioner "Fylkesmannsembetet". The first step in the WFD Implementation in Norway is to charaterize the catchment-areas and the water recipients in the nine Water regions. Based on todays situation, and the deviation from the expected natural state, the needs for and the extent of precautions will be identified to reach the environmental goals. Based on the water quality-quantity relations in the catchment areas / watershed, an action-plan will be pre-pared. The action-plan will ensure that the objectives will be fulfilled. Establishment of tar-gets and a monitoring program will be made for all the catchment areas / watershed. The tar-gets are planned to be reached within 15 Years (2015). To define a goal for water status, a water classification system are created. A GIS-tool has been made and distributed to all coun-ties for QA and input of additional regional/local information.
Forfattere
Anne-Grete Buseth Blankenberg Ketil Haarstad Anne-Kristine SøvikSammendrag
Agricultural runoff contributes with significant amounts of nitrogen (N) to rivers and lakes causing water quality problems. Constructed wetlands (CWs) in first- and second order streams reduce downstream loading of nutrients through mechanisms such as sedimentation, uptake by vegetation and microbial denitrification. (A stream with no tributaries (headwater stream) is considered a first order stream. A segment downstream of the confluence of two first order streams is a second order stream [1]). Norwegian CWs are often too small to easily achieve high N-retention. It is therefore important to improve and optimize the N-retention processes in the CWs where the CW area cannot be increased due to local restrictions. The main aim of this project was to compare N-retention in an experimental wetland including eight different types of organic and mineral CW-filters, one of which was a standard Norwegian CW (depth 0.5 m). The average total-N retention through the experimental wetland was 17 % for the period of May-September in 2003, but only 2% in the same period in 2004. Converted to mass, the retention in 2003 was 168 kg and 26 kg in 2004. Lower retention in 2004 was probably mainly caused by higher hydraulic load that year. The organic filters performed better than the mineral filters and the standard CW.
Forfattere
Anne-Grete Buseth Blankenberg Ketil Haarstad Bent C. BraskerudSammendrag
Pesticide losses to the environment are unwanted due to possible environmental and health hazards. An experimental wetland is established to study the efficiency with respect to retention of sediments, nutrients and pesticides. Pesticides were applied on an arable soil plot in the watershed. Statistical analyses were carried out on three selected pesticides; propachlor, metalaxyl and chlorfenvinfoss. All pesticides were found in the experimental wetland, with peak concenttrations shortly after spraying. In 2003 pesticide retention varied from 11% to 42% and in 2004 retention varied from 19% to 56 %. Comparing eight different wetland filters, we found that L6 and L8, with flagstones and straw, respectively, had a higher total pesticide retention than a standard Norwegian wetland (L4). When the compounds were treated separately, however, the picture was different. Statistical analyses showed that the treatments were signficantly different from zero in six of the wetlands for remowal of propachlor, for removal of metalaxyl none were significantly different, and for removal of chlorfenvinphos four treatments were significantly different. For the three compounds none of the relative treatments were significantly different from L4. Chemical properties of the pesticides could explain some of the behaviour in the watershed and in the wetland.
Forfattere
Dag-Ragnar BlystadSammendrag
Bringebær er det av bærslagene våre som er mest utsatt for virusproblemer. Det skyldes både at vi har mye villbringebær som fungerer som reservoar for virus og vektorer og at bringebær står lenge i feltet. Bringebær kan infiseres av forskjellige virus med forskjellig spredningsmåte: jordboende, nematodeoverførte virus; bladlusoverførte virus og pollenoverførte virus. Det viktigste bekjempelsestiltaket er å starte med friskt plantemateriale.