Map visualisation service (WMS) of the dataset: Zone of uncertainty of the regulatory zoning of the risk prevention plan of the landslides of the Côte d’Île-de-France sector Vallée de la Marne Tranche 3

The studies carried out in the context of the development of the PPRn GT of the Côte d’Île-de-France (map of hazards) were carried out on the scale of the 1/10 000th, and mapped on the IGN scan25 background enlarged to the 1/10 000th. As the regulatory zoning results from the crossing of the hazard map and the stakes map, the accuracy of this mapping cannot be greater than that of hazards. As a result, the scale of use of regulatory zoning is that of 1/10 000th and exploitation on a finer cadastral scale (1/5000 or 1/2000) is not recommended. The accuracy of the initial data therefore presents uncertainty about its contours in the order of 10 meters. Genealogy: The boundaries of a restricted area are represented on the graphical documents of the RPP. Regulatory limits are generally set on natural phenomena, which do not follow cadastral or administrative boundaries. A PPR determines the boundaries of the different restricted areas based on the calculated right-of-way of the site’s hazardous phenomena. Some PPRs may sometimes contain regulations associated with linear or punctual figures (cavities, runoff axis...). The linear and point graphics primitives are to be used in these cases respectively.