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Constructing the first municipal-level GIS for France and a multi-modal transport network

Constructing the first municipal-level GIS for France and a multi-modal transport network

Digitising the French État-Major maps as a collaboration with OpenHistoricalMap

OHM+ANR_COMMUNESThe French road network c.1750 has been digitised from the Cassini maps by Perret et al. from the National Geographic Institute (IGN). For the nineteenth-century road network, some digitisation projects have extracted data for a few geographical areas such as the département of Île-de-France and, specifically, the city of Paris. We aim to fill these gaps and complete the road network for the mid-nineteenth century, using French military maps (Etat-Major maps) for the period from 1820 to 1866. The EM map series are water-colored military maps produced throughout the nineteenth century (from 1820 to 1866) and cover- ing the entire French metropolitan territory. They were drawn at scales ranging from 1:40,000 to 1:50,000, mostly for areas around Paris, and 1:80,000, almost everywhere else. The maps are multi- themed. They show nineteenth-century land use with features such as forests, buildings, fields, or marshes; linear transport networks, from small paths to different types of roads and railway tracks; but also all waterways and contemporary administrative boundaries for the whole of mainland France.

The work required to digitise a full road network from 273 map sheets meant that we had to enlist the help of a larger group of volunteers. For this task we partnered with OpenHistoricalMap (OHM) to set up a crowd-sourcing project.

Open Historical Maps

OHM is a free, open, and interactive platform for collaborative mapping of world history based on the OpenStreetMap technology and community. At its core, the story of OHM (and OSM) is less of a core spatial technology problem and more of how technology best matches human needs. Many of these requirements are reflected in our project: the need for the highly scalable and concurrent creation of GIS-based data by a large and distributed team.


Get involved

Before you start digitising, you will have to create your own (free) OHM account, using this link:

If you have never used OHM, or are new to this project, all you need to get you going (properly) is included in the following set of slides. Please make sure you read them before you start digitising!

Once you have an account on OHM, please let us know so we can keep you up to date with our mapping activities and progress, using the button below.

Register your interest

Getting started on OHM

Please read this page carefully before you start, and if you have not participated in one of our training session make sure you consult the attached file, which recapitulates all you need to know to get stared.

The project is currently available for two regions:

1. Hauts-de-France : click here to access the project.

2. Bourgogne-Franche-Comté : click here to access the project.