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
Bjørn ØklandSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Aksel OpsahlSammendrag
When you care about data integrity of spatial data you need to know about the limitations/weaknesses of using simple feature datatype in your database. For instance https://land.copernicus.eu/pan-european/corine-land-cover/clc2018 contains 2,377,772 simple features among which we find 852 overlaps and 1420 invalid polygons. For this test I used “ESRI FGDB” file and gdal for import to postgis. We find such minor overlaps and gaps quite often, which might not be visible for the human eye. The problem here is that it covers up for real errors and makes difficult to enforce database integrity constraints for this. Close parallel lines also seems to cause Topology Exception in many spatial libraries. A core problem with simple features is that they don't contain information about the relation they have with neighbor features, so integrity of such relations is hard to constraint. Another problem is mixing of old and new data in the payload from the client. This makes it hard and expensive to create clients, because you will need a full stack of spatial libraries and maybe a complete locked exact snapshot of your database on the client side. Another thing is that a common line may differ from client to client depending on spatial lib, snapTo usage, tolerance values and transport formats. In 2022 many system are depending on live updates also for spatial data. So it’s big advantage to be able to provide a simple and “secure” API’s with fast server side integrity constraints checks that can be used from a standard web browser. When we have this checks on server side we will secure the equal rules across different clients. Is there alternatives that can secure data integrity in a better way? Yes, for instance Postgis Topology. The big difference is that Postgis Topology has more open structure that is realized by using standard database relational features. This lower the complexity of the client and secures data integrity. In the talk “Use Postgis Topology to secure data integrity, simple API and clean up messy simple feature datasets.” we will dive more into the details off Postgis Topology Building an API for clients may be possible using simple features, but it would require expensive computations to ensure topological integrity but to solve problem with mixing of new and old borders parts can not be solved without breaking the polygon up into logical parts. Another thing is attribute handling, like if you place surface partly overlapping with another surface should that have an influence on the attributes on the new surface. We need to focus more on data integrity and the complexity and cost of creating clients when using simple feature, because the demands for spatial data updated in real time from many different clients in a secure and consistent way will increase. This will be main focus in this talk. https://www.slideshare.net/laopsahl/dataintegrityriskswhenusingsimplefeaturepdf
Sammendrag
Denne rapporten oppsummerer to interessegruppemøter arrangert for landbruket. Noen brukerbehov kan innfris innenfor prosjektene, men det er sprik mellom hva forskningsprosjekter kan levere og hva interessegruppen har behov for, slik at ikke alle ønsker kan innfris. Enkelte ønsker har blitt videreformidlet til værvarslingstjenesten. Som et svar på brukerbehov etter interessegruppemøtet i 2022 beregnet vi tetraterm (varmekrav for ulike treslag i sommermånedene), inkludert endringer i tetraterm over tid. Tetratermen har økt i hele landet, og med det øker den potensielle utbredelsen av varmekjære trær. I den nettbaserte versjonen av rapporten (https://storymaps.arcgis.com/stories/d4bddb92349e4e4baf24b20fdaf2ad24) beskrives også eksisterende dataportaler mer inngående, noe interessegruppen har etterspurt.
Forfattere
Jiangsan ZhaoSammendrag
Det er ikke registrert sammendrag
Forfattere
Paal KrokeneSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Mladen Ognjenović Ivan Seletković Nenad Potočić Mia Marušić Melita Perčec Tadić Mathieu Jonard Pasi Rautio Volkmar Timmermann Lucija Lovreškov Damir UgarkovićSammendrag
European beech (Fagus sylvatica L.) forests provide multiple essential ecosystem goods and services. The projected climatic conditions for the current century will significantly affect the vitality of European beech. The expected impact of climate change on forest ecosystems will be potentially stronger in southeast Europe than on the rest of the continent. Therefore, our aim was to use the long-term monitoring data of crown vitality indicators in Croatia to identify long-term trends, and to investigate the influence of current and previous year climate conditions and available site factors using defoliation (DEF) and defoliation change (DDEF) as response variables. The results reveal an increasing trend of DEF during the study period from 1996 to 2017. In contrast, no significant trend in annual DDEF was observed. The applied linear mixed effects models indicate a very strong influence of previous year drought on DDEF, while climate conditions have a weak or insignificant effect on DEF. The results suggest that site factors explain 25 to 30% DEF variance, while similar values of conditional and marginal R2 show a uniform influence of drought on DDEF. These results suggest that DEF represents the accumulated impact of location-specific stressful environmental conditions on tree vitality, while DDEF reflects intense stress and represents the current or recent status of tree vitality that could be more appropriate for analysing the effect of climate conditions on forest trees.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag