Netherlands Journal of Geosciences — Geologie en Mijnbouw | 92 – 4 | 217-241 | 2013 3D geology in a 2D country: perspectives for geological surveying in the Netherlands M.J. van der Meulen1,*, J.C. Doornenbal1, J.L. Gunnink1, J. Stafleu1, J. Schokker1, R.W. Vernes1, F.C. van Geer1,2, S.F. van Gessel1, S. van Heteren1, R.J.W. van Leeuwen1, M.A.J. Bakker1, P.J.F. Bogaard1, F.S. Busschers1, J. Griffioen1,2,3, S.H.L.L. Gruijters1, P. Kiden1, B.M. Schroot1,4, H.J. Simmelink1, W.O. van Berkel1, R.A.A. van der Krogt1, W.E. Westerhoff1 & T.M. van Daalen1 1 TNO Geological Survey of the Netherlands, P.O. Box 80015, 3508 TA Utrecht, the Netherlands 2 Faculty of Geosciences, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, the Netherlands 3 Deltares, P.O. Box 85467, 3508 AL Utrecht, the Netherlands 4 Currently at EBN, P.O. Box 19063, 3501 DB Utrecht, the Netherlands * Corresponding author. Email: [email protected] Manuscript received: June 2013; accepted: November 2013 Abstract Over the last ten to twenty years, geological surveys all over the world have been entangled in a process of digitisation. Their paper archives, built over many decades, have largely been replaced by electronic databases. The systematic production of geological map sheets is being replaced by 3D subsurface modelling, the results of which are distributed electronically. In the Netherlands, this transition is both being accelerated and concluded by a new law that will govern management and utilisation of subsurface information. Under this law, the Geological Survey of the Netherlands has been commissioned to build a key register for the subsurface: a single national database for subsurface data and information, which Dutch government bodies are obliged to use when making policies or decisions that pertain to, or can be affected by the subsurface. This requires the Survey to rethink and redesign a substantial part of its operation: from data acquisition and interpretation to delivery. It has also helped shape our view on geological surveying in the future. The key register, which is expected to start becoming operational in 2015, will contain vast quantities of subsurface data, as well as their interpretation into 3D models. The obligatory consultation of the register will raise user expectations of the reliability of all information it contains, and requires a strong focus on confidence issues. Building the necessary systems and meeting quality requirements is our biggest challenge in the upcoming years. The next step change will be towards building 4D models, which represent not only geological conditions in space, but also processes in time such as subsidence, anthropogenic effects, and those associated with global change. Keywords: Netherlands, applied geoscience, hydrogeology, geological surveying, mapping, geomodelling, geodatabase Introduction the responsibilities associated with this new status, the Survey is reconsidering and redesigning its operation and in that process Scope a new, or at least sharper picture is emerging of geological surveying in the future. Pursuant to a new law that will become effective in 2015, These developments set the final stages of a process of DINO, the national Dutch subsurface database operated by the modernisation that geological survey organisations all over the Geological Survey of the Netherlands, is to become an official world are currently entangled in (Allen, 2003; Jackson, 2010). government register (a ‘key register’ / basisregistratie). In facing Most surveys are replacing paper archives that were built in the 217 Netherlands Journal of Geosciences — Geologie en Mijnbouw 92 – 4 | 2013 course of many decades by electronic databases; many surveys Future tasks and responsibilities started producing electronically distributed 3D subsurface models in addition to or instead of 2D geological maps that were Once the BRO is established, subsurface data gathered by any their primary output since their establishment. For a variety of Dutch government body will have to be submitted to the reasons explained below, the Dutch survey is among the early Geological Survey, stored in the BRO database, which in its turn adapters in both respects. has to be consulted by the government when making policies In this overview paper we present the Geological Survey of or decisions that pertain to, or can be affected by the subsurface. the Netherlands as a working example of a geological survey The BRO will contain the following types of data: in transition. The overall structure of the paper is based on – Survey data (verkenningen): borehole (including sample the following three questions: 1) Where do we stand? (as an analyses), cone penetration testing, well log, seismic, geo- organisation, then focussing on data management, information electric. technology and subsurface modelling); 2) What enabled us to – Models (modellen): three of the national geological models get where we are? (trends and enabling factors); and 3) Where (‘3D maps’) that the geological survey develops and/or do we go? (outlook and perspectives). The overarching question maintains, as well as national geomorphological and soil we address is: how can a geological survey exploit modern maps of Alterra (part of Wageningen University and Research information technology to its fullest potential, while building Centre, WUR). on and maintaining consistency with its legacy of (pre-digital) – Rights of use (gebruiksrechten), i.e. exploration and data and information products? production licenses for hydrocarbons, minerals and geothermal heat (Mining Act, outlined below) and A transition in the delivery of subsurface groundwater-abstraction permits (Water Act). information – Constructions (constructies): constructions that serve to extract substances from the subsurface (e.g. hydrocarbon A key register is an officially appointed register containing and groundwater wells), store substances in the subsurface, high-quality data that the government is obliged to use for its or monitor subsurface processes (e.g. provincial and national public tasks. The objective of a key registry is to enhance monitoring networks for soil quality, groundwater quality efficiency in data management and to avoid error in use, as and groundwater levels). often encapsulated in the concept of ‘capture once, use many times’. Current key registers, linked in one comprehensive The BRO will initially consist of the contents not only of information system (stelsel van basisregistraties), contain DINO, but also of BIS, the Dutch national soil survey database personally identifiable information (PII); identification and operated by Alterra. Just as DINO, BIS contains a combination ownership of real estate, companies and vehicles; real-estate of basic data (borehole descriptions) and their interpretations value; income, employment relations and social-security (soil, geomorphological and groundwater regime maps). The benefits; addresses and buildings; and base topography. pedological and geomorphological content of the BRO will DINO’s upgrade to a key register for the subsurface, further however not be further discussed in this paper on geological referred to by its Dutch acronym BRO (basisregistratie onder - surveying. grond), recognises the government’s reliance on subsurface The key-register status brings new responsibilities to all data and information for a number important planning and parties involved. Up until now, there are only two types of data permitting procedures (e.g., for land use planning; exploration that are stored in DINO by legal obligation: data from ground - and production of hydrocarbons, minerals and geothermal heat; water monitoring networks established under the Water Decree storage of CO2 and natural gas; and groundwater management). (Anonymous, 2009), and data obtained from exploration and Beyond that, it is expected to help reduce the considerable production licensed under the Mining Act (Anonymous 2002). societal risks and costs associated with adverse ground This act applies to minerals and hydrocarbons deeper than 100 conditions in public works, especially infrastructure projects. A m below the surface, storage of substances in the same depth societal cost-benefit analysis (maatschappelijke kosten-baten - range, and for geothermal energy to targets deeper than 500 m. analyse, MKBA), an obligatory step in the preparation of certain The BRO extends such obligation to virtually all data and government policies and investments, showed that the benefits information we manage: the Survey will have to handle and of the BRO are higher than its costs (Terpstra et al., 2011). The store substantially more data and its user group will not only BRO will also be instrumental in implementing the European become larger, but also more diverse. Current users are mostly INSPIRE directive for subsurface data in the Netherlands specialists, who will inevitably be joined by new users who are (INSPIRE arranges for an all-encompassing European spatial less familiar with subsurface data, or with the subsurface data infrastructure; Anonymous, 2007). altogether. At this moment, for example, DINO is used by only a few of the 415 Dutch municipalities that will all have to use the BRO in the near future. 218 Netherlands Journal of Geosciences — Geologie en Mijnbouw 92 – 4 | 2013 While the Survey is responsible for quality control, levels at or below sea level. The remaining part of the country responsibility for data in the BRO rests with the providers consists almost entirely of Pleistocene