PPRI perimeter of the Somme Valley

This dataset contains the boundaries at the different stages of the development of the PPRN. The characteristic of these perimeters is to be the consequence of an official act and to produce their effects from a specified date. This is the:- prescribed perimeter set out in the Prescribing Order of a PPR (natural or technological);- scope of exposure to risks that corresponds to the scope regulated by the approved RPP. This approved perimeter is a utility easement (PM1 for PPRNs and PM3 for PPRTs);- scope of study that corresponds to the envelope in which the hazards were studied.

本数据集收录了PPRN在不同开发阶段的各类边界。此类边界的核心特征为：其产生源于法定行为，并自指定日期起产生法律效力。具体涵盖以下三类边界：
1. 由PPR（自然类或技术类）划定令所载明的法定划定边界；
2. 与经核准的RPP所规制的风险暴露范围相一致的风险暴露范围，该经核准的边界属于公用设施地役权（其中PPRN对应PM1，PPRT对应PM3）；
3. 与开展灾害研究所涉及的包络范围相匹配的研究范围。