The Geomodelling expert group of the Geological Survey of the Netherlands (GDN) has developed various models of the Dutch subsurface. In doing so, we are helping to find answers to social issues that exist within ministries, local governments, and commercial parties regarding the use of the subsurface and its consequences.

Statutory tasks to map the subsurface

To map the subsurface, we use all available data from the National Key Registry of the Subsurface (BRO). This is the national database of subsurface data that is managed by GDN in accordance with statutory requirements, and which exists to provide the most accurate representation of the subsurface of the Netherlands. Using this database, we are able to estimate the structure and properties of the layers across the three domains of shallow, medium, and deep, as well as the groundwater present in them  . We publish these models and the predictions they make through various online portals.

Advice by detailing national subsurface models

Our subsurface models are the starting point when advising on subsurface issues. We can, for example, depict the structure of the subsurface under dikes in much more detail by adding local data from drillings and core penetration tests (CPTs), and by interpreting CPTs using  machine learning  techniques. More insight into the structure of the subsurface also results in more detailed subsequent geotechnical calculations. An example of this is the ‘Sterke Lekdijk’ project.

Innovations enabled through research

Research supports both our statutory tasks and our consultancy role. We are, for example, doing research on the different ages of groundwater reserves. In this, we have discovered that tracers can be effectively used to determine the age of groundwater. The knowledge we gain from this not only helps us to better understand the groundwater system; it also gives water companies insight into the possible contamination risks of the drinking water they pump up.

GeoTOP model with drilling logs.

Understanding opportunities and risks

The models we develop can be used to answer specific questions. For example, about the risks of operations in the deep subsurface, which aquifers are suitable for the production of geothermal energy, or what the best places from which to extract gravel, sand, clay, limestone, and groundwater are. These interpretations of subsurface models are freely available through DINOloket. Of course, we also use them ourselves when offering advice.

Challenges for the future

The subsurface will play an increasingly central role in various social issues, such as the energy transition and climate adaptation. Simultaneously, the user group of our subsurface models is changing as a result of the National Key Registry of the Subsurface (BRO). Those changing demands require innovations in our modelling methods. 

Regarding geothermal energy, for example, the transition between the moderately deep and deep subsurface is particularly interesting. We therefore aim to expand our knowledge of these layers and to represent them in our subsurface models by linking different models and using new data types. 

The dynamics of stakeholder questions also demand a different working pace. Where in the past we had two to three years to model a new GeoTOP model area, the time in which subsurface data needs to be available is becoming shorter. This is why we are actively looking for new modelling techniques to accelerate the modelling process and improve the models.

Cross-section deep subsurface.

Are you interested in our work in the field of Geomodelling?

Please contact research manager and head of mapping, Denise Maljers, using the blue ‘mail directly’ button below.

A glimpse behind the scenes at the Geomodelling expert group