Dataset Direct Download Service (WFS): Zone d’aléa du PPRT of the establishment RHODIA in the municipality of La Rochelle, in Charente-Maritime

Area exposed to one or more hazards represented on the hazard map used for risk analysis of the RPP. The hazard map is the result of the study of hazards, the objective of which is to assess the intensity of each hazard at any point in the study area. The evaluation method is specific to each hazard type. It leads to the delimitation of a set of areas on the study perimeter constituting a zoning graduated according to the level of the hazard. The allocation of a hazard level at a given point in the territory takes into account the probability of occurrence of the dangerous phenomenon and its degree of intensity. For PPRTs the hazard levels are determined effect by effect on maps by type of effect and overall on an aggregated level on a synthesis map. All hazard areas shown on the hazard map are included. Areas protected by protective structures must be represented (possibly in a specific way) as they are always considered subject to hazard (case of breakage or inadequacy of the structure). Hazard zones can be described as developed data to the extent that they result from a synthesis using multiple sources of calculated, modelled or observed hazard data. These source data are not concerned by this class of objects but by another standard dealing with the knowledge of hazards. Some areas within the study area are considered “no or insignificant hazard zones”. These are the areas where the hazard has been studied and is nil. These areas are not included in the object class and do not have to be represented as hazard zones.本类数据对象指用于RPP风险分析的灾害地图（hazard map）上标注的、遭受一种或多种灾害影响的区域。 灾害地图是灾害研究的成果，其核心目标为评估研究区域内任意点位的各类灾害强度。针对不同灾害类型，需采用专属评估方法，最终在研究范围内划定出按灾害等级梯度划分的若干分区。在研究区域内的指定点位确定灾害等级时，需综合考量该危险现象的发生概率及其强度等级。 针对PPRTs，需按每种灾害效应分别在对应地图上确定灾害等级，并在综合地图上按聚合层级进行整体定级。 灾害地图上标注的所有灾害影响区域均需纳入本类对象。受防护结构保护的区域也必须予以标注（可采用特定标注方式），因为即便有防护结构，该区域仍存在遭受灾害影响的可能（如结构发生破损或防护不足的情况）。 灾害区域可被视为经过开发的数据集，其生成依赖于对多源计算、建模或观测得到的灾害数据的综合整合。此类源数据不属于本类对象的范畴，而是由另一项用于灾害认知的标准进行规范。 研究区域内的部分区域被归类为“无灾害或灾害影响可忽略区域”。这类区域经研究确认不存在灾害风险，因此无需纳入本类对象，也无需作为灾害区域进行标注。