Map Viewing Service (WMS) of the dataset: Risks of the PPRi de la Loire, Val de Briare

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 multi-random PPRNs, each zone is usually identified on the hazard map by a code for each hazard to which it is exposed. 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. However, in the case of natural RPPs, regulatory zoning may classify certain areas not exposed to hazard as prescribing areas (see definition of the PPR class).

本类对象指用于RPP风险分析的灾害地图中所标注的、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，其研究目标为评估研究区域内任意点位处各类灾害的强度。评估方法因灾害类型而异，最终会在研究范围内划定一系列区域，形成按灾害等级分级的灾害区划。在某一特定地域点位分配灾害等级时，需综合考虑该危险现象的发生概率及其强度等级。
针对多随机PPRN，灾害地图上的每个区域通常会通过其暴露的各类灾害对应的编码进行标识。本类对象涵盖灾害地图上标注的所有灾害区域。受防护结构保护的区域也必须予以标注（可采用特定方式），因为即便有防护结构，仍可能因结构破损或失效而面临灾害风险。
灾害区划可被视为衍生数据集，其来源于对多源计算、建模或观测得到的灾害数据的综合整合。本类对象不涉及上述源数据，相关源数据由另一项针对灾害认知的标准规范。研究区域内部分区域被视为“无灾害或灾害可忽略区域”，即经研究确认灾害强度为零的区域，此类区域不纳入本类对象，也无需作为灾害区域进行标注。但对于天然RPP而言，监管区划可能将部分未受灾害影响的区域划为规定性区域（详见PPR类别的定义）。