Flanders’ underground landscape comes to the surface


A research team assembled and digitised all existing data on Flemish soil, creating a geological 3D model – a first

Even more refined version to be completed by 2017

According to a common saying, residents of Flanders live “on Flemish clay”. But in addition to just clay, the region’s soil packs multiple layers of rock formations, some of which formed hundreds of millions of years ago. For the first time, a new geological model is rendering this entire underground landscape visible in 3D.

The 3D model, which can be consulted on Databank Ondergrond Vlaanderen (Flanders Soil Database), divides the Flemish soil into 38 coloured layers according to the age of the rock. The oldest and hardest layers of rock are more than 400 million years old and can be found up to a depth of 6,400 metres. The most recent layers belong to the geologic Quaternary Period, which began about 1.8 million years ago.

The 3D model casts the Flemish soil as a pistol of sorts. The pistol grip is located below the eastern province of Limburg, and the barrel ends with the coast of West Flanders. Below the visualised layers, the Flemish soil is composed of old rock. It was deposited more than 400 million years ago and weren’t incorporated into the model.

“In Limburg, both the deep basin of the Kempen and the Roer Valley Graben are responsible for the large variety of old rock,” explains geology expert Roel De Koninck, who co-ordinated the model’s final development phase at the Flemish Institute for Technological Research (VITO). ”In the basin of the Kempen, many layers date from 400 to 150 million years ago.”

It took VITO six years and a team of five scientists to create the 3D model, which is part of a long-term assignment of the Natural Resources division of the Flemish government’s Environment, Nature and Energy department. For this task, VITO’s Flemish Knowledge Centre Soil, receives an annual budget of €900,000 from the government of Flanders – half of which was spent on developing the model.


During the six years of research, the researchers assembled and digitised all the existing data on Flemish soil. “Among our sources were maps more than 60 years old, drilling data dating from two centuries ago and seismic analyses,” says De Koninck. 

Our sources included maps more than 60 years old, drilling data from two centuries ago and seismic analyses

- Roel De Koninck

While fragmented, much of the knowledge was already accessible through the government’s database, but the team also searched the archives of research bureaus and private companies. One of the organisations that provided helpful info was gas transport and distribution company Fluxys. 

To visualise the 3D model’s enormous amount of data, the Natural Resource Division uses the freely downloadable programme 3D SubsurfaceViewer. Developed by the German company INSIGHT, this viewer makes consulting underground information in 2D and 3D easy. The software tool also allows users to make vertical and horizontal cross sections across the entire region. 

Among those who will most benefit from the model are research bureaus that study soils for large infrastructure projects for buildings, bridges, roads and tunnels, for example. The model can give them an initial idea of the soil, which is useful for analyses of the required stability conditions. 

Online tool

Research bureaus could also use the model for studies on the presence of groundwater and possibilities for natural gas storage or geothermal energy use. Among the research centres that will use the model are the Geological Survey of Belgium, the Dutch Organisation for Applied Scientific Research, the Royal Meteorological Institute of Belgium and the Belgian Nuclear Research Centre (SCK-CEN). The SCK-CEN could use the model as a data source for its own specialised research – to examine the possibilities for underground storage of radioactive waste, for instance.

The current models of different regions and countries are not yet attuned to each other

- Griet Verhaert

But consulting the model should just be the starting point for any research process, says Griet Verhaert from the government’s Natural Resources division. “Experts will always need to combine the general knowledge of the model with detailed maps or precise drilling,” she explains.

Although the model only offers a broad overview of the underground layers, scientists could also use the online tool for their research. “It, for example, provides insights into the way that layers spread throughout Flanders over the course of time,” Verhaert says.

University professors could also use the model in their classes, as could secondary school teachers. “By replacing abstract maps with the engaging model on the 3D SubsurfaceViewer, we could help teachers interest students,” says Verhaert.

The model could show students, say, just how far the sea reached into Flanders millions of years ago, when the region was partly underwater. The Kempen basin and the Roer Valley Graben, both clearly visible in the model, are shown to be made from rock that washed in during that period. The model also illustrates how rivers and valleys formed during the previous ice age.


According to Verhaert, the geological model could be particularly useful for final year students in secondary schools and those in higher education because it requires a basic knowledge of geology.

In 2010, the Natural Resources division launched the Ik Doorgrond Vlaanderen (I Get to the Bottom of Flanders) website, which targets secondary school students of all ages. The site features playful videos by Flemish celebrities, like comedian Gunter Lamoot, on, for instance, how raw materials such as clay are used to make roof tiles. Verhaert is considering linking the new geological model to this existing website.

Still, the 3D model ought to be considered not as a finished product but as a foundation for a more refined tool. By 2017, the VITO team is scheduled to complete an updated version that shows the characteristic differences between the underground clay, sand and loam layers.

“Professionals who need info on the groundwater could, for example, benefit from the data on the permeability of rocks,” explains De Koninck.

“The new model will also considerably help advance our own expertise on raw materials,” Verhaert adds.

Geological structures of course don’t end with the borders of a region. “But the current models of different regions and countries are not yet attuned to each other,” Verhaert explains. The Flemish Natural Resources division is currently working with partner organisations in the Netherlands to address the problem. The idea is to connect the regions on the Flemish-Dutch border so that the two models can be joined in one underground landscape. The first project, which tackles the Roer Valley Graben models, should be completed by next spring.

Urban mining

Together with public waste management agency Ovam, the Flemish government’s Environment, Nature and Energy department recently organised a congress on urban mining – the process of recycling materials from products, buildings and waste. About 300 participants exchanged experiences at the congress, called “The quest for resources in Flanders”, which was held in Mechelen.

By translating the principles to culture and education policy, we can introduce their essence in families’ homes

- Joke Schauvliege

Urban mining is especially interesting for regions and countries with no large natural reserves in  silver and lead – like Flanders. The region has already experimented with several innovative strategies to recycle materials with the aim of becoming less dependent on imports. In her address, Flemish environment minister Joke Schauvliege highlighted the results of the Flemish Materials Programme, which started in 2012.

In September, the department of environment also signed an agreement with industry federation Agoria to halt the illegal export of waste through Flemish ports. The advantages run in two directions – preventing damage to environments abroad and promoting the recycling of valuable materials in Flanders.

The minister also pointed out that the government has adjusted the legal framework to make collection of small electronic waste easier. Co-ordinated by environmental organisation Bond Beter Leefmilieu, the “consusharing” project will also encourage residents of Flanders to “consume together” through sharing, lending or letting.

One of Ovam’s contributions was the development of the SIS Toolkit, an instrument to better integrate sustainability principles into the design and innovation processes of businesses. Together with the Enterprise Agency, Ovam also developed the Materials Scan for small- and medium-sized Flemish businesses. 

A European hub

The Flemish Symbiose platform was also established at the initiative of, among others, essenscia, the Belgian umbrella organisation for the chemistry and life sciences sector. Symbiose enables businesses to exchange waste, so that what one company discards, another uses as a resource. The CORE Business project has a similar intent but targets industries that use synthetic materials and textiles.

In her speech, Schauvliege said that attention should shift to Europe and that every effort should be made to make Flanders a European hub for the management of sustainable materials. Schauvliege, also Flanders’ culture minister, also emphasised the need for a “sustainability culture” in Flanders. “By translating the principles from the sustainable materials policy to culture and education policy, it’s possible to introduce their essence in families’ homes,” she said.

Research team converts data on Flemish soil into 3D model – a first

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