Natural risk zoning: Indre River PPRN hazard zone outside castelroussine agglomeration

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 assignment 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 to be subject to hazard (cases of breakage or inadequacy of the structure).The hazard zones may be classified as data compiled in so far as they result from a synthesis using several sources of calculated, modelled or observed hazard data. These source data are not covered by this class of objects but by another standard dealing with the knowledge of hazards.Some areas of the study perimeter are considered “zero 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).指用于RPP风险分析（risk analysis）的灾害分布图（hazard map）上标注的、受一种或多种灾害影响的区域。该灾害分布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的各类灾害强度。评估方法因灾害类型而异，可基于灾害等级对研究范围内的多个区域进行划定，形成分级分区。针对区域内指定点位的灾害等级赋值时，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场景，各分区通常会在灾害分布图上通过其受影响的各类灾害对应的编码进行标识。灾害分布图上标注的所有灾害影响区域均纳入该对象类（object class）。受防护结构保护的区域必须（可采用特定方式）予以标注，因为即便设置了防护结构，仍存在结构破损或失效的可能，此类区域仍被视为处于灾害影响范围内。灾害影响区域可按数据类型进行分类，前提是该区域基于多源计算、建模或观测得到的灾害数据综合生成。此类源数据不属于该对象类的范畴，而是由另一项针对灾害认知的标准进行规范。研究范围内的部分区域被视为“零灾害或微灾害区域”，即经研究确认无灾害影响的区域。此类区域不纳入该对象类，也无需作为灾害影响区域进行标注。但针对天然RPP场景，监管分区可能将未受灾害影响的部分区域划定为规定区域（详见PPR类别（PPR class）的定义）。