HisGIS.nl provides a national digital infrastructure for research, policy development, and the creation and promotion of interest in the historic landscape and related built environment of the Netherlands. The project is based on the digitised and vectorised maps and tables of the oldest, so-called Napoleonic cadastre from around 1832, which was introduced in large parts of Europe following French instructions. The purpose of this cadastre was to introduce a new and fair system of taxing land and buildings. It consisted of three pillars that formed an indivisible whole: the measurement of parcels (shown on maps), the registration of ownership and land use (in tables), and a complex system of valuation of types of parcels (documented in a series of municipal reports). The HisGIS.nl project is aimed at national and international (historical, economic, archaeological, sociological, geographical, and ecological) researchers, volunteers, interested citizens, (local) governments and third parties developing (commercial) services for any of the above-mentioned groups.

The development of the HisGIS.nl platform has taken place over several decades and has been significantly expanded, especially in recent years, through the commitment and funding of (regional) governments, volunteers, researchers, and other parties. In 2019, the project was officially handed over from the Fryske Akademy in Leeuwarden to the Humanities Cluster of the Royal Netherlands Academy of Arts and Sciences (KNAW) in Amsterdam. However, years of fragmented investment have had a profound impact on the project's underlying infrastructure. Data access is cumbersome by today's standards, older files need quality improvement, and resources for large-scale infrastructure improvements are lacking. These challenges are being addressed head-on by a new and substantial round of national investment in HisGIS.nl for the years 2023-2025, which will allow us to make the data and platform consistent, sustainable and well-functioning, and to provide a fully national infrastructure environment. At the end of this investment round, we will have georeferenced all 16,000 cadastral maps of the Netherlands, both urban and rural, and provide a central access point for all vectorised parcels (estimated at around 60% of 3,000,000 by the end of 2025) and related registers.

Here we would like to present the full scope of the HisGIS.nl project, which in its current state is a fully functional and widely used research infrastructure project, as well as our plans for the coming years. We will focus on five key components of the project: The georeferencing of the cadastral maps (Figure 1) using a new IIIF-based georeferencing tool from AllMaps which will be specially adapted to the specific difficulties associated with cadastral maps; the vectorisation of the parcels drawn on these maps using a custom-built OpenStreetMap environment (Figure 2); digitising the full registers, the Oorspronkelijk Aanwijzende Tafels or Original Designating Tables (Figure 3), as well as the reports and tables associated with the valuation of the parcel categories; providing a data output pipeline that allows the data to be interoperable with other datasets and a wide range of file formats (from shapefiles to CSV and RDF); and managing a unique and bespoke citizen science platform that we have developed to work with our pool of volunteers. We will also discuss why we have decided against using (semi)automatic feature extraction and transcription methods, at least so far, and have instead chosen to invest in better data entry tools.

As the French-style cadastre has been implemented in a virtually uniform manner across Europe, our project infrastructure and data models can be applied to non-Dutch contexts with very little additional investment. However, our integral approach of combining all three pillars of the French cadastre (maps, tables and valuation documentation) in one system and data model sets HisGIS.nl apart from most other European projects using the 19th century Napoleonic cadastre (e.g., Michelin and Chadeyron 2020; Département Vaucluse 2017; Hauts-de-Seine le Département 2020; Uhrmacher and Kass 2016–2024). The over-focus on only one pillar - usually only the maps, or only the summary assembly maps (Michelin and Chadeyron 2020) - is most evident in the digitisation efforts of the Napoleonic cadastre outside the Netherlands. The archival scans of the Napoleonic cadastre focus almost exclusively on the maps (‘Cartesius’, n.d.; FranceArchives 2024; ‘Le Géoportail National Du Grand-Duché de Luxembourg’, n.d.; ‘Feuilles Cadastrales Historiques: Urplaeng’ 2022). Ignoring the cadastral tables and the wealth of related documents, however, deprives us of essential knowledge for fully understanding and using the cadastre and, we would argue, for efficiently digitising cadastral data. It also drastically limits the potential uses of the data. In our presentation we will briefly address these use cases in the Netherlands, which are much broader than academic use and range from commercial archaeology to policy making, based on our experience so far.

Figure 1. Cadastral map of the municipality Stad Almelo

Figure 2. The digitised Napoleonic cadastre for the region around Amsterdam (ca. 1832).

Figure 3. Original Designating Table of the municipality Zijpe.

Bibliography
‘Cartesius’. n.d. http://www.cartesius.be/CartesiusPortal/#.
Département Vaucluse. 2017. ‘Cadastre Napoléonien Géo-Référencé de Vaucluse’. https://maps.vaucluse.fr/index.php/view/map/?repository=archives&project=cadastre_georeference.
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Hauts-de-Seine le Département. 2020. ‘Cadastre Napoléonien (Assemblage Départemental)’. https://opendata.hauts-de-seine.fr/explore/dataset/fr-229200506-cadastre-napoleonien-assemblage-departemental/information/.
‘Le Géoportail National Du Grand-Duché de Luxembourg’. n.d. https://geoportail.lu/.
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