Risks of the PPRi de la Loire val d’Orléans (upstream)

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).

本类区域指用于RPP风险分析的灾害地图上所标示的、受一种或多种灾害影响的区域。该灾害地图源自灾害专项研究，其核心目标为评估研究区域内任意点位的各类灾害强度。不同灾害类型对应专属的评估方法，基于该方法可在研究范围内划定若干区域，形成按灾害等级分级的灾害分区。对区域内指定点位的灾害等级进行赋值时，需综合考量该危险现象的发生概率及其强度等级。
针对多随机PPRN场景，灾害地图上的每个分区通常会通过对应其所受灾害的专属编码进行标识。灾害地图上标注的所有灾害区域均需纳入本数据集。受防护结构保护的区域即便处于防护状态，也需（可采用特定标注方式）纳入展示——因防护结构可能发生破损或失效，此类区域仍被视作受灾害影响的范围。
灾害分区可被视为经加工的数据集，其生成过程需整合多源的计算、建模或实地观测所得的灾害数据。本类数据集不涵盖上述源数据，相关源数据需遵循另一项针对灾害认知的专项标准进行管理。研究区域内部分区域被划为无灾害或灾害影响可忽略区域，此类区域已完成灾害评估且确认无灾害风险，因此不属于本数据集范畴，无需作为灾害分区进行标注。但针对天然RPP场景，监管分区可能将部分未受灾害影响的区域划定为规定管控区域（详见PPR类别的定义）。