“Digital land models” group


The group “digital land models” formed within the Paris Time Machine project pursues the objective of constituting geomatically exploitable references concerning the 3D aspect of the maps of Paris and the Seine department produced in the 19th century.

Relief has indeed a very specific history within that of cartography. Its theoretical invention can be dated back to the end of the 18th century with the altitude line as a graphic process of restitution (Ducarla, 1782) then theorized mathematically (Lacroix, 1804). The first large-scale practical experiment dates from the very beginning of the 19th century with a map of Paris with altitude levels (Girard, Verniquet, 1810). Relief maps were a skill mastered by the “Ponts et Chaussées et des Mines” engineering corps until the end of the century, when the military geographers began to produce staff maps with altitude lines. Concerning in a general way the development of the territory (roads, railroads, canals, quarries, landfills, urban renewal and extension works, etc.), they provide a 3D spatial and historical framework that renews the themes approached until then with the only two-dimensional map: archaeology,
hydrology, geology, pollution, metabolism, etc. The work of the group aims to provide a gateway to the historical urban environment, potentially exploitable in a diachronic perspective.
The working group is setting up a data process based on geographic information systems that is fitted to this type of map including, on the basis of digitized versions, georeferencing, estimation of data error margins, data entry, conversion of altimetric systems, valorization in
a form comparable to current standards (digital terrain model – DTM -) (Fernandez, 2018), dissemination.

Four references were selected (Girard and Verniquet, 1810), (Delesse, 1858, 1880), (Inspection générale des carrières, 1994). An exchange with the “Atelier parisien d’urbanisme” allows us to have the most accurate reference, which is a DTM with a spatial resolution of 1 m over the Paris area. The input data allowed us to create three DTMs as
historical references. The relief at the beginning of the 19th century on the Fermiers Généraux right-of-way and the relief of the second half of the 19th century on the right-of-way of the Seine department are derived from the interpolation of historical data measured by the engineering corps at those times. The paleo-relief on the Paris right-of-way is modeled by interpolating data from the IGC, which are contemporary but time-staggered measurements of the elevation of the roof of the geological substratum, measured during the course of various soundings and works carried out in Paris. The table below shows the main operations performed from these historical sources to obtain DTMs.

It should be noted that altimetry systems are a rather complex page in the history of 19th century techniques and that a synthesis has been produced for Paris. It allows to make centimetric conversions between the five systems successively used between 1805 and 2019 and finally to make the different historical sources containing altimetric values communicate with each other.


The report of this working group is available here.

Team members

Mathieu Fernandez (Post-doctoral researcher)

Hélène Noizet (Associate Professor HDR, Université Paris1 Panthéon Sorbonne, LAMOP)

References

DELESSE A., 1858, Carte hydrologique de la ville de Paris : 1858. Publiée d’après les ordres de Mr le baron G. E. Haussmann, préfet de la Seine et exécutée par Mr Delesse ; dessinée par Al. Babinski, F. Savy, Paris, 1 Pl.

DELESSE A., 1880, Carte géologique cotée du département de la Seine représentant le gypse, le calcaire grossier et la craie, d’après les ordres de M. Hérold, sénateur, préfet de la Seine, conformément à la décision du conseil général, L. Wuhrer, Paris, 1 Pl.

DUCARLA M., 1782, Expression des nivellemens ou méthode nouvelle pour marquer rigoureusement sur les cartes terrestres et marines les hauteurs et les configurations du terrein, Dupain-Triel, Paris, 111 p.

FERNANDEZ M., 2018, « La strate du sol d’une mégapole : observations localisées sur l’Anthropocène. Topographie et morphologie des couches préindustrielle et industrielle à Paris », Géocarrefour. En ligne (consulté le 09-09-2019) : https://journals.openedition.org/geocarrefour/12016

GIRARD P.-S., VERNIQUET E., 1810, Plan de nivellement général de la ville de Paris rapporté sur l’Atlas du plan général de la ville de Paris de Verniquet, [s. é.], Paris. Manuscrit : BHVP FOL AT 157

INSPECTION GÉNÉRALE DES CARRIÈRES (IGC), 1994, Atlas géologique de la Ville de Paris au 1/5000e, Mairie de Paris, Paris

LACROIX S.-F., 1804, Introduction à la géographie mathématique et critique, in PINKERTON J., Géographie moderne, Dentu, Paris, T.1, (CCXIV + 229) p.