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.为编制法兰西岛沿海区域PPRn GT（风险地图）所开展的研究，均采用1:10000比例尺完成，并以放大至1:10000的法国国家地理研究院（Institut Géographique National，IGN）scan25地理底图作为制图基底。由于管制区划由风险地图与承灾体地图叠加生成，该制图的精度不得高于风险地图本身。因此，管制区划的适用比例尺为1:10000，不建议使用更精细的地籍比例尺（1:5000或1:2000）开展应用。初始数据的轮廓精度存在约10米级的不确定性。 数据谱系：受限区域的边界在RPP图形文档中予以标注。管制边界通常依托自然现象划定，并不遵循地籍或行政边界。PPR通过计算场地危险现象的防护通行范围，确定各类受限区域的边界。部分PPR有时会包含与线性或点状要素（空腔、径流轴等）相关的管制条款，此类场景下应分别使用线性图元和点图元进行表达。