Dataset : Digitized inventory of the French peatlands of 1949

Digitization and georeferencing of public map data. Bibliographic data collection.
The atlas was scanned at the Maison des Sciences de l'Homme et de l'Environnement Claude Nicolas Ledoux in Besançon. The mapping work was carried out on the QGIS 2.18 software (QGIS Development Team, 2009. QGIS Geographic Information System. Open Source Geospatial Foundation. URL http://qgis.osgeo.org) the repository used is the Lambert 93, EPSG-2154.
The images have been georeferenced as raster using road and bridge crossings as reference points. The atlas maps are sometimes not very accurate, in particular because of the gluing of the staff maps together, which causes shifts of a few millimetres. The reference background used was therefore the aerial photographs of the 1950s (IGN Raster2018, orthoimagery.orthophotos. 1950-1965), faithfully georeferenced with respect to the current orthophotos. The degree of accuracy of the atlas maps required a distortion of the initial image using the Thin Plate Spline transformation and the nearest neighbor resampling method when executing the "georeference" command.
According to the georeferenced maps, the polygons of peaty areas were diverted at a scale of 1:25,000 to form a shapefile layer by referencing the code indicated on the map. These polygons have sometimes been repositioned to correspond to their position indicated on the map and in the book's comments, in relation to the IGN background. The attribute table was then attached, giving for each site its code, the name of the watershed, the surface, the average thickness and the volume of peat of the site, as well as a column of remarks. The watershed name refers to the chapter of the book from which the data is taken, and makes it easy to find other data about the site.