The model ‘Nederland 3D’ (NL3D) provides three-dimensional insight into the subsurface of the mainland of the Netherlands. It ranges from down to 50 meters below NAP (Dutch Ordnance Level) to the top of the Vaalserberg at 325 meters above NAP. The model provides information on layer structure and soil type (e.g. clay, sand, peat).
In NL3D, the subsurface is divided into a regular three-dimensional grid (raster) of contiguous voxels (volume cells) measuring 250 x 250 x 1 meter. Each voxel contains a set of properties. These are the lithostratigraphic or geologic unit (layer) to which a voxel belongs, the lithological class (soil type) representative of the voxel, and a number of attributes that together form a measure of model uncertainty.
Basic data
To create NL3D, a geological layer model was first constructed. This was done by upscaling the existing layer model DGM v2.2 to the desired resolution of 250 x 250 meters.
The modeling of lithological class in NL3D is based on an extensive dataset. This includes borehole descriptions of about 507,000 boreholes from the DINO database, about 125,000 boreholes from the Laaglandgenese database of Utrecht University and about 6,700 boreholes for the province of Utrecht in the Utrecht peat meadow area. For each borehole interval, the layer model was used to determine within which geological unit (layer) it falls. In addition, from the lithological borehole the lithological class is derived.
Based on the geological layer model, each voxel of the voxel model was placed in the appropriate geological unit. Then, for each geological unit, the lithological class of the voxels was estimated based on the borehole intervals of that particular unit.
Difference between NL3D and GeoTOP
NL3D has a lower resolution than GeoTOP. GeoTOP uses more geological guidance (information from other sources, such as maps and publications) and more advanced interpretation of borehole descriptions. It also distinguishes more layers, including anthropogenic deposits, which have their own lithological class in GeoTOP. In general, more detail is visible in GeoTOP. NL3D is therefore especially suitable for applications where a nationwide result is needed, or for applications in areas where GeoTOP is not yet available.
Application and reliability of model results
When using NL3D – as for GeoTOP – always keep in mind that it is a regional model. It is not suitable for use on a local scale; generating a local subsurface model always requires additional data.
For applications in which the geological layer structure is important, it is preferable to use DGM. This is because NL3D is based on a upscaled version of layer model of DGM v2.2. In this upscaling, information is lost.
Availability
NL3D is delivered as a set of 2D raster maps representing the attributes of the voxel model (geological unit, most probable lithological class and model uncertainty of lithological class) at a given depth relative to subsurface. Because NL3D is less accurate than GeoTOP, it was decided to make NL3D available to a maximum depth up to 15 meters below subsurface. The maps can be viewed on DINOloket and can also be downloaded there for use in one's own GIS application.
Reports
The Totstandkomingsrapport (PDF in Dutch - 4.4 MB) provides a detailed description of the creation of the geological subsurface model NL3D: it describes what the model is, what source data it is based on, how it was created and what the differences are with the previous version. The report also includes a brief geological description of the model.
Current and previous versions
On the Subsurface Models page, NL3D version 2.0 (2024) can be viewed and downloaded. Earlier versions can be requested via the contact form.
Citation
TNO – GDN (2024) NL3D. TNO – Geological Survey of the Netherlands, https://www.dinoloket.nl/en/subsurface-models/map; visited yyyy-mm-dd.
Contact
If you have a question or notice something wrong, please let us know via the contact form.