future view

Reliable data of the subsurface is priceless

30 September 2019 • 4 min reading time

The Netherlands is the first country in the world to commission a complete register of its subsurface through a legislative act, by means of the ‘Dutch Key Register of the Subsurface’. The Geological Survey of the Netherlands (GDN), part of TNO, develops and manages this register and is also producing a three-dimensional image of the subsurface. The subsurface plays an increasingly important role in a number of major social issues. More and more parties therefore refer to GDN for advice before they start developing a site.

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The importance of the subsurface is clearly revealed in major social themes such as climate change and the energy transition. The effects of climate change on the subsurface are clear. For example, as dikes lose a lot more moisture during dry periods, they crack more easily and hence more likely to be breached.


However, the subsurface can also form part of the solution. For example, the government and industry have serious plans to store large quantities of CO2 underground in order to reduce national CO2 emissions. The energy transition is also forcing us to find more sustainable forms of energy generation, such as the use of geothermal energy for the industry and our homes.

All these developments require up-to-date and accurate data of the subsurface and the same applies to new building projects, infrastructure such as motorways and tunnels, and the quality of the drinking water supply, to name just a few.


Over the years, the Netherlands has amassed a huge database of information on the Dutch subsurface: the DINO database, a freely available resource. “Colleagues from abroad were already jealous because the Netherlands was the first country to build such a central database,” said Mirjam Bartels, Research Manager with the DINO department. “We are also the first country in the world to commission a complete register of the subsurface in a legislative act. The government implemented this legislation due to TNO’s advice. We are proud to have been tasked with managing the Register of the Subsurface, an important part herein being the provision of advice to users plays an important role.”


“It was a logical choice for the Ministry of the Interior and Kingdom Relations to ask us to manage the register,” says Tirza van Daalen, director of the GDN. “The GDN was established in 1903, which means we have more than a century of experience of surveying the subsurface, managing the associated data and advising public authorities and businesses. The fact that we can now apply our expertise to the development of the register is a fantastic next step.”

HUGE database

The GDN is currently populating the register with data in conjunction with the source owners. This is a gradual process, and will be completed by the end of 2022. “Insofar as you can call it complete,” adds Bartels. “Of course, a database like this will always be under development and new categories will be added along the way. For example, there are already plans to include data on soil contamination in the register. It’s going to end up being a huge database! Just to compare: the government maintains nine such registers for everything that happens aboveground, while there is only one for subsurface: the Register of the Subsurface. Experts predict that this single database will be almost as large as the nine aboveground registers combined.”


“The register supplements all the data we have already collected over the years,” emphasizes Hans van der Ven, product manager with the GDN. “Our central database also contains information that has not been officially validated by source owners, but which may still be of interest to certain parties. They can use this information to gain more insight into socially relevant issues. For example, subsurface data could help to facilitate the energy transition and other efforts to ensure a sustainable future for the Netherlands. We have also created three-dimensional images of the subsurface to make the information easier to interpret for a wider audience. All this data is freely available and will remain so. As the work continues, we will be able to offer more and more validated information thanks to the creation of the register and the legal obligation for source owners to provide data for it.”

“The subsurface plays an important role in our daily lives,” he continues. “The foundations of our homes, the water from our taps, the gas we use to cook, the food on our plates, the forests where we recreate and the roads we drive on are all examples of services that require accurate data about the subsurface. We believe it is important that everyone has access to the data on the Dutch subsurface and that this data is also used. So, alongside professional users, the general public also has free access to our database. And that will remain to be the case.”


Returning to the dikes mentioned at the beginning of this article, it was revealed how data can produce important insights about such flood defences a few years ago when a Proof of Concept was developed for the dike along the river Lek. De Stichtse Rijnlanden water board and the Register of the Subsurface Programme were considering whether to increase the height of the dike, a decision where  there was much at stake: if the dike was breached, a large part of the Randstad conurbation could be flooded, potentially even reaching as far as Amsterdam. Based on the digital information about the subsurface, it was revealed that the dike did not need to be raised but rather strengthened. Thanks to the register, the specialists did not have to inspect every square meter of the 55-kilometre-long dyke to reach this conclusion. This shows how priceless accurate data on the subsurface can be, and this is just one of many examples of the benefits of the register.

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Geological Survey of the Netherlands
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