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.
2008
Forfattere
Bagher Farmani Nils-Otto Kitterød Henk KeersSammendrag
Flow parameters in the vadose zone of an ice-contact delta near Oslo"s Gardermoen Airport were estimated by inverse flow modeling combining time-lapse ground-penetrating radar (GPR) travel-time (TT) tomography and groundwater (GW) table data. Natural water infiltration from the 2006 snowmelt was used as the upper boundary condition in forward flow simulations. The lower boundary condition was the outflux of water from the vadose zone derived by time derivative of the GW table. The inverse flow modeling was done using different combinations of time-lapse GPR TT tomography and time series of the level of the GW table. The purpose was to assess the improvements in parameter estimations and the information value of the different data sets. Flow parameters estimated by conditioning only on time-lapse GPR TT tomography capture the development of the wet front but fail to simulate the GW table fluctuations. Inverse flow modeling conditioned on only GW table did not simulate the wet front correctly but decreased the objective function better than conditioning on time-lapse GPR data. If the inversion is conditioned on both time-lapse GPR data and the GW table fluctuations, the final estimates of the flow parameters are close to the estimates from the inversion conditioned on only GW table data. This result was obtained because the moving GW table was monitored continuously in time while the GPR data were sampled only three times during the infiltration event; thus, observations of the GW table had higher weights in the objective function than did observations derived from GPR tomograms. Finally, we did forward flow modeling with the estimated parameter sets and compared the flow paths with an independent tracer experiment performed at the field site in 1999. The results showed that anisotropy in the intrinsic permeability was an important parameter that should be considered when simulating the flow paths. However, volumetric soil water content distribution is not strongly related to the anisotropy of intrinsic permeability. Therefore, anisotropy cannot be correctly estimated by inverse flow modeling conditioned on volumetric soil water content only.
Forfattere
Nils-Otto KitterødSammendrag
Hensikten med denne rapporten er å gi hydrogeologisk bakgrunnsmateriale til Bergen kommune i saksbehandlingen av det planlagte garasjeanlegget i Fløyfjellet. Basert på foreliggende informasjon er det beregnet sannsynlige effekter av en ny tunnel på vannbalansen i løsmassene ved Bryggen. Dersom vannlekkasjene i den nye tunnelen blir i samme størrelsesorden som i den eksisterende jernbanetunnelen, vil grunnvannssenkningen i løsmassene ved Bryggen bli meget beskjedne i forhold til de naturlige variasjonene i grunnvannstanden. Med de forutsetningene som er lagt inn i strømningsmodellen vil sannsynlige senkninger av grunnvannstanden bli i størrelsesorden 5 % av gjennomsnittlig naturlig grunnvannstand. Dette tilsvarer i underkant av 2 cm i forhold til gjennomsnittlig naturlig grunnvannstand nær kaikanten.
Forfattere
Nils-Otto KitterødSammendrag
Denne rapporten sammenstiller eksisterende kunnskap om hydrogeologiske forhold i nedbørsfeltet til Bryggen i Bergen. Det er lagt vekt på informasjon som er viktig for å forstå grunnvannstrykket og strømningsforholdene i Fløyfjellet. Kunnskapssammenstillingen vil danne utgangspunkt for numeriske eksperimenter hvor hensikten er å simulere endringer i grunnvannstrykket som kan oppstå ved konstruksjon av nye fjellanlegg i Fløyfjellet. Grunnvannstrykket i fast fjell er en av faktorene som bestemmer vannbalansen i løsmassene i Middelalderbyen i Bergen. Grunnvannet i fast fjell i nedbørsfeltet til Bryggen er lite undersøkt. Det foreligger imidlertid en god del indirekte informasjon som kan benyttes for å avgrense problemet og som dessuten kan benyttes for å anslå størrelsesorden på viktige inngangsparametre til numeriske beregninger. Hensikten med dette notatet er å sette foreliggende informasjon i sammenheng og dermed beskrive strømningsforholdene gjennom en begrepsmessig modell.
Forfattere
Bjørn FrantzenSammendrag
Omhandler entusiasten Piotr Zaborchikov sine private restaureringsarbeider knyttet til gamle trebygninger i landbyen Varzuga i Terskij kommune, Murmansk fylke i Russland på sørsiden av Kolahalvøya, en pomorlandsby ved Kvitsjøens kyster. På engelsk og russisk.
Forfattere
Ricardo HolgadoSammendrag
I verdensmålestokk er potetcystenematoder (PCN) (Globodera spp.) Kjent som alvorlige skadegjørere på potet. Nematodenes sterke spesialisering til potet som vertsplante har ført til en overlevelsesevne i jord som er stor utfordring for potetdyrkingen. Virulente populasjoner som kan oppformeres på resistent potet er en annen grunn for bekymring. Både den gule arten (yPCN) G. rostochiensis og den hvite arten (wPCN) G.pallida er klassifisert som karanteneskadegjørere og er regulert i Matloven. Bekjempelse av ikke virulent (yPCN) bygger på vekstskifte med resistent potet, ikke-vertsplanter og mottakelig potet. Bekjempelse av wPCN gjøres i dag ved at infiserte bruksenheter legges i karantene i 40 år med dyrkingsforbud for vertsplanter og annen aktivitet som risikere å sprede nematoden.
Forfattere
Sonja KlemsdalSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.
Forfattere
Peder LombnæsSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag