Dataset Direct Download Service (WFS): Areas of hazard of the PPRi of Val du Louet and Confluence of Maine and Loire

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).本数据集指代用于RPP风险分析的危险地图（hazard map）上标注的、暴露于一种或多种危险的区域。 危险地图源自危险专项研究，其目标为评估研究区域内任意点位的各类危险强度。评估方法因危险类型而异，可在研究范围内划定若干区域，形成按危险等级分级的区划方案。对辖区内特定点位的危险等级进行赋值时，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PPRNs，危险地图上通常会通过专属代码标识每个区域所暴露的各类危险。 危险地图上标注的所有危险区域均需纳入本数据集。受防护结构保护的区域也必须（可采用特定标注方式）标注为危险区域，因为此类区域始终存在受危险影响的可能性（如防护结构发生破损或失效的情况）。 危险区划可被视为衍生数据，其源自对多源计算、建模或观测得到的危险数据的综合处理。本数据集类不涵盖这些源数据，源数据由另一项针对危险认知的标准规范进行管理。 研究区域内部分区域被归类为‘无危险或危险可忽略区域’，即经专项研究确认危险程度为零的区域。此类区域不纳入本数据集类，也无需作为危险区域进行标注。但对于天然RPP，监管区划可将未暴露于危险的部分区域归类为规定区域（详见PPR类的定义）。