Zeeland and Goeree-Overflakkee updated in GeoTOP

Zeeland and Goeree-Overflakkee updated in GeoTOP

The Geological Survey of the Netherlands (GDN) has completely updated the Zeeland and Goeree-Overflakkee area in its 3D shallow subsurface model, GeoTOP. This innovation provides valuable information for anyone dealing with issues involving the shallow subsurface in that area.

Following the 2020 expansion of GeoTOP to include North Brabant and North and Central Limburg, the decision was made to update the oldest two model areas, which were already published in 2008: Zeeland and Goeree-Overflakkee. Modelling techniques and geological insights have changed in the meantime. Moreover, a lot of new drilling data has become available since 2008: 41,500 drilling descriptions were now available instead of 23,500. The new model incorporates the new data and insights and also applies the latest modelling techniques. With this, these two areas meet the National Key Registry of the Subsurface (BRO) quality requirements.

Important for salinisation issues

For Zeeland and Goeree-Overflakkee, this new version of GeoTOP is valuable for projects that involve salinisation, but also for dyke management and spatial planning. In addition, the latest subsurface insights from GeoTOP can be used for issues of energy, infrastructure, and for groundwater studies.

Next step: from Almere to East Netherlands

Next up to be updated in GeoTOP is the area surrounding Almere. It is an experiment to develop a small model area in a short time (one year) to quickly respond to current developments (in this case, the municipality of Almere’s Masterplan Ondergrond (‘Subsurface Master Plan’)). Meanwhile, the modelling of the IJsselmeer region and East Netherlands has been started, giving GeoTOP national coverage (with the exception of South Limburg).

About GeoTOP

GeoTOP is a 3D model of the shallow subsurface of the Netherlands created by GDN. In this model, the subsurface of the Netherlands up to a maximum of 50 metres below sea level is divided into blocks of 100 x 100 x 0.5 metres. Each block provides information on layer composition and soil type (sand, gravel, clay, or peat). Based on hundreds of thousands of drilling descriptions, subsurface composition and characteristics were estimated for each block. GeoTOP has been included in the National Key Registry of the Subsurface (BRO) since 2020. This means, among other things, that administrative bodies are obliged to use the model for spatial issues. Soil and water will be guiding spatial planning in the coming years. It is therefore crucial to have a picture and understanding of that subsurface.

Want to know more?

View or download the BRO model GeoTOP (version 1.5) with the updated model area Zeeland and Goeree-Overflakkee on DINOloket or BROloket. You can also download the model there and use it in your own GIS software, for example. Want to know more or do you have any questions? Please contact the Service Desk.