Dataset Direct Download Service (WFS): PPRN Alea Saumurois Coteau (Saumur)

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。该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处各类灾害的强度。评估方法因灾害类型而异，其会在研究范围内划定若干区域，形成一套按灾害等级分级的区划方案。对某一给定地域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，灾害地图上的每个区域通常会通过其所对应受影响灾害的专属编码进行标识。
本数据集涵盖灾害地图上标注的全部灾害影响区域。受防护结构保护的区域亦须（可采用特定方式）予以标注，因此类区域始终被视为存在灾害风险，例如防护结构发生破损或防护不足的情形。
灾害区域可被视为经加工处理的数据集，其基于多源计算、建模或观测所得的灾害数据综合生成。此类源数据不属于本对象类别的范畴，而是由另一项针对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“无灾害或灾害可忽略区域”，即经研究确认灾害影响为零的区域。此类区域不属于本对象类别的范畴，无需作为灾害区域进行标注。但针对天然RPP场景，监管区划可将未受灾害影响的部分区域归类为指定管控区域（详见PPR类别（PPR class）的定义）。