Regulated area of the PPRN of the catchment area of the Lézarde — Seine-Maritime

For natural PPRs, the Environmental Code defines two categories of zones (L562-1): risk-exposed areas and areas that are not directly exposed to risks but where measures can be foreseen to avoid exacerbating the risk.
Depending on the hazard level, each area is subject to an enforceable settlement. The regulations generally distinguish three types of zones:
1- ‘Building prohibited areas’, known as ‘red areas’, where the hazard level is high and the general rule is the prohibition on construction;
2- ‘prescribed areas’, known as ‘blue zones’, where the hazard level is average and the projects are subject to requirements adapted to the type of issue;
3- areas not directly exposed to risks but where constructions, works, developments or farms, agricultural, forestry, craft, commercial or industrial could aggravate risks or cause new ones, subject to prohibitions or requirements (cf. Article L562-1 of the Environmental Code). The latter category applies only to natural RPPs.

针对自然风险预防区域（Natural PPRs），《环境法典》第L562-1条将区划划分为两类：受风险直接影响区域，以及未直接承受风险但可采取措施避免风险加剧的区域。
依据危险等级差异，每类区划均需遵循具有强制执行力的管控要求。相关法规通常将区划细分为三类：
1. 建筑禁建区（又称"红色区域"）：该区域危险等级较高，通用规则为禁止开展任何建设活动；
2. 规划管控区（又称"蓝色区域"）：该区域危险等级中等，建设项目需遵循适配风险类型的具体管控要求；
3. 非直接受风险影响区域：该区域虽未直接承受风险，但农业、林业、手工业、商业或工业类建设工程、开发项目或农场运营可能加剧既有风险或引发新风险，因此需遵守禁建或管控要求（参见《环境法典》第L562-1条）。此类区划仅适用于自然风险预防区域（Natural RPPs）。