Country Specific – Norway

Quick Facts NDH DTM1

Cell Size1x1 m
Coordinate SystemETRS89 / UTM 33N
Vertical ReferenceNN2000
Flight Years2016–present

Our elevation model of Norway is based primarily on the DTM1 data made available by Kartverket's nasjonal detaljert høydemodell (NDH) project, and has a grid resolution of 1x1 meter. The project started in 2016 and currently covers most of Norway. More data is being acquired continuously. We strive to keep our model up to date with the latest sources.

In order to use an elevation model for hydrological analysis such as watershed and flow accumulation computations, two primary conditions need to be met:

  • The upstream area of any river should be covered by the elevation model.
  • Structures on top of the terrain should only be present in case they actually block water from flowing under or through them.

Below, we discuss how we process the model to fulfill these conditions as well as possible.


In order to cover all of Norway including upstream areas of all rivers, we have extended the DTM1 model in the following areas:

  • For Sweden we use Lantmäteriet's Laserdata Nedladdning, skog point cloud where available.  In the figure below, this area is highlighted in green.
  • For remaining areas of Norway and Sweden not covered by the NDH/DTM1 data, we have used the Kartverket's DTM 10 data set from 2013.
  • To cover the upstream area of the Vefsna river (Nordland) in Sweden, we have included some data from the 30m EU-DEM data set, which in turn is based on SRTM and ASTER GDEM data (yellow in the figure below).
  • To cover the upstream area of the Tana and Neiden rivers (Finnmark), we have included parts of the national Finnish elevation models:

A full overview of which data source is used for which part of the model is available by clicking the gear icon next to an elevation layer, selecting the "Source" tab, and "Show source information". Use point query to see more details for individual areas as provided by Kartverket. Multiple styles are available for this layer to colour sources by e.g. collection date. Note that the DTM 10 data set is not shown since it's used everywhere no other data set was available.

Overview of sources used for the elevation model.


Apart from vegetation and major bridges, also buildings have been removed from the terrain model during construction. When computing water flow paths, more realistic results are generally obtained when the elevation model includes buildings as water can be simulated to flow around them. In SCALGO Live, we accomplish this by adding buildings back into the model using a data set of building footprints,. Here, we raise all grid cells covered by a building to a height of 10 m above the highest terrain point within the building footprint. This model is called Terrain/Buildings and is the basis for all nationwide hydrological computations.

The building footprint data set used is the FKB N5 Bygning data set from Kartverket/Geovekst.

Flow paths routed around buildings.

Bridges, underpasses and hydrological corrections

Major bridges have generally been removed from the model, but for many smaller bridges and underpasses, additional hydrological corrections that allow water to flow through such structures may be necessary. SCALGO Live Norway includes a nationwide hydrological correction set based primarily on the N20 Vann layer from Kartverket/Geovekst, as well as culverts (stikkrenner) from Statens Vegvesen's NVDB, Elveg 2.0  and the Banenettverk dataset from Bane Nor SF.

Corrections have been generated at locations where rivers intersect roads or railroads, as well as at river sections marked subsurface ("medium=U") where the river e.g. runs through a longer covered/piped area. Secondly, corrections have been generated at road overpasses and tunnels.  Thirdly, NVDB's stikkrenner are included.

Each correction thus follows a line in the river or road network, or a known culvert, with end points adjusted to match the elevation model as well as possible. In places where the elevation model is already hydrologically corrected (e.g. at large bridges), corrections are not generated.

This data set is machine-generated, so some errors should be expected. However, since we only include corrections along known river and road lines, we believe it to be conservative in terms of water flow.

The set of corrections is available under the Hydrological Corrections category in the Library.

The national analyses use these corrections, and workspaces created using the predefined "Flash Flood Map" or "Sea-Level Rise" buttons also include them by default. If you create a workspace through any other means than the predefined buttons (e.g. if you upload your own model), you can include corrections in that workspace through the workspace Actions tab by clicking Import corrections, they will not be included automatically.

Corrections and flow accumulation around Burudelva and Engabekken in Lommedalen.

Land cover

The land cover map in SCALGO Live is produced by SCALGO based on machine learning techniques at a resolution of 25 cm.  We refer to the land cover section for more details.

Soil type

SCALGO Live uses the superficial deposits from Geological Survey of Norway for watershed soil type query. NGU's quaternary geological mapping (superficial deposits mapping) shows which type of soil predominates in the upper meters of the terrain surface. Thick and thin layers of other soil types may appear farther down the soil profile.  When used in the SCALGO analyses, we map the NGU soil type to the set of SCALGO soil types. For more information about these, see the soil type documentation. The mapping from NGU soil type to SCALGO soil type is available in the table below.

We refer to Geonorge for more information about the NGU source data.

NGU nameSCALGO Soil Type
14-Avsmeltningsmorene (Ablasjonsmorene)Coarse clay with sand
130-Bart fjellBedrock
110-Bart fjell/fjell med tynt torvdekke, uspesifisertBedrock
140-Bart fjell/fjell med usammenhengende eller tynt løsmassedekkeBedrock
31-Breelv- og bresjø-/brekammeravsetning (Glasifluvial og glasilakustrin avsetning)Fine sand
21-Breelv- og elveavsetningFine sand
20-Breelvavsetning (Glasifluvial avsetning)Fine sand
30-Bresjø- eller brekammeravsetning (Glasilakustrin avsetning)Clay
36-Bresjø-/brekammer og innsjøavsetning (Glasilakustrin og lakustrin avsetning)Clay
16-DrumlinCoarse clay with sand
50-Elve- og bekkeavsetning (Fluvial avsetning)Fine sand
305-Fjellskredavsetning, stedvis med stor mektighetGravel
306-Fjellskredavsetning, usammenhengende eller tynt dekkeGravel
53-Flomavsetning bresjøtapning (uspesifisert)Fine sand
54-Flomavsetning fra bresjøtapping, sammenhengendeFine sand
55-Flomavsetning fra bresjøtapping, usammenhengende eller tynt dekke over berggrunnenFine sand
57-Flomavsetning, usammenhengende eller tynt dekkeFine sand
71-ForvitringsmaterialeCoarse sand with clay
70-Forvitringsmateriale, ikke inndelt etter mektighetCoarse sand with clay
73-Forvitringsmateriale, stein- og blokkrikt (blokkhav)Coarse sand with clay
72-Forvitringsmateriale, usammenhengende eller tynt dekke over berggrunnenCoarse sand with clay
120-Fyllmasse (antropogent materiale)Coarse sand with clay
41-Hav- og fjordavsetning, sammenhengende dekke, stedvis med stor mektighetClay
40-Hav- og fjordavsetning, uspesifisertClay
43-Hav-, fjord- og strandavsetning, usammenhengende eller tynt dekke over berggrunnenClay
0-Ikke angittBedrock
35-Innsjøavsetning (Lakustrin avsetning)Clay
301-Jord- og flomskredavsetningFine sand
302-Jord- og flomskredavsetning, usammenhengende eller tynt dekkeFine sand
315-Jordskred- og steinsprangavsetning, stedvis med stor mektighetGravel
316-Jordskred- og steinsprangavsetning, usammenhengende eller tynt dekkeGravel
303-Leirskredavsetning, stedvis med stor mektighetClay
304-Leirskredavsetning, usammenhengende eller tynt dekke over berggrunnenClay
1-Løsmasser/berggrunn under vann, uspesifisertBedrock
42-Marin strandavsetning, sammenhengende dekkeFine sand
122-Menneskepåvirket materiale, ikke nærmere spesifisertFine clay with sand
11-Morenemateriale, sammenhengende dekke, stedvis med stor mektighetCoarse clay with sand
12-Morenemateriale, usammenhengende eller tynt dekke over berggrunnenCoarse clay with sand
10-Morenemateriale, uspesifisertCoarse clay with sand
15-Randmorene/randmorenesoneCoarse clay with sand
17-RogenmoreneCoarse clay with sand
22-Ryggformet breelvavsetning (Esker)Coarse clay with sand
102-Sammenhengende løsmassedekke av flere jordarterClay
80-Skredmateriale, ikke inndelt etter mektighetGravel
81-Skredmateriale, sammenhengende dekkeGravel
82-Skredmateriale, usammenhengende eller tynt dekkeGravel
313-Snø- og jordskredavsetning, stedvis med stor mektighetFine sand
314-Snø- og jordskredavsetning, usammenhengende eller tynt dekkeFine sand
317-Snø- og steinsprangavsetning, stedvis med stor mektighetFine sand
309-Snøskredavsetning, stedvis med stor mektighetFine sand
310-Snøskredavsetning, usammenhengende eller tynt dekkeFine sand
321-Steinrikt, sigende skråningsmaterialeGravel
311-Steinskredavsetning, stedvis med stor metighetGravel
312-Steinskredavsetning, usammenhengende eller tynt dekkeGravel
307-Steinsprangavsetning, stedvis med stor mektighetBedrock
308-Steinsprangavsetning, usammenhengende eller tynt dekkeBedrock
37-Strandavsetning innsjø og/eller bresjøFine sand
90-Torv og myrGyttja/peat
100-Tynt dekke av organisk materiale over berggrunnBedrock
101-Usammenhengende eller tynt løsmassedekke over berggrunnen, flere løsmassetyper, uspesifisertBedrock
60-Vindavsetning (Eolisk avsetning)Fine sand