Dataset Direct Download Service (WFS): 10 meter uncertainty band PPRi Vitry-le-François — Saulx sector

The studies carried out in the context of the development of the Vitry-le-François PPRi (map of hazards) were carried out on the scale of 1/10 000th, and mapped on a background IGN scan25 enlarged to 1/10 000th. Since regulatory zoning stems from the intersection of the hazard map and the stake map, the accuracy of this mapping cannot be greater than that of the hazards. Consequently, the scale of use of the regulatory zoning is that of 1/10 000 and exploitation on a smaller cadastral scale (1/5000 or 1/2000) is not recommended. However, municipalities wishing to do so may transpose the regulatory map into their planning documents provided that they comply with operating principles in order to take account of the uncertainty associated with the expansion of the zoning, particularly at the boundary of the area. Indeed, it is not possible to improve the accuracy of the initial data which presents uncertainty about its contours of the order of 10 metres, which is relatively important on the scale of a plot in an urbanised area. The transposition of the regulatory map into a cadastral planning document cannot therefore be limited to a mere enlargement, which would result in a false precision of the contours. Therefore, a guide defines the principles that would allow municipalities who wish to do so, a transposition into an urban planning document (PLU, municipal map) taking into account the uncertainties between each area. It must also make it possible to define the area regulation to be applied when considering planning permissions.围绕维特里勒弗朗索瓦风险预防规划（PPRi）的风险地图编制工作所开展的研究，均采用1:10000比例尺，并以放大至1:10000比例尺的法国国家地理研究院（IGN）scan25扫描底图作为制图基底。鉴于监管区划由风险地图与承灾体分布图叠加生成，其制图精度不得高于风险地图本身。因此，监管区划的适用比例尺为1:10000，不建议以更小的地籍比例尺（1:5000或1:2000）开展实际应用。不过，有意向的市镇可将监管地图纳入其规划文件，但需遵循相关操作原则，以考量区划范围扩张所伴随的不确定性，尤其是在区域边界处。 初始数据的轮廓存在约10米的不确定性，这一误差在城市化区域的地块尺度下相对显著，因此无法对其精度进行优化。 因此，将监管地图直接转绘至地籍规划文件绝非简单的比例尺放大，否则会导致边界精度虚高的问题。据此，一份指南明确了相关操作原则，允许有意向的市镇将监管地图适配至城市规划地方指导文件（PLU，Plan Local d'Urbanisme，市镇规划图）中，同时兼顾各区域间的不确定性；此外，该指南还需明确在审批规划许可时应适用的区域监管规则。