Simple download service (Atom) of the dataset: Strategic noise map type C according to the Lden indicator (evening day-night). Prefectural Order No 71-2018-07-13-005 of 13 July 2018.

The European Directive 2002/49/EC on the assessment and management of environmental noise aims at a harmonised assessment of exposure to noise in the Member States. It defines them as representations of data describing a noise situation according to a noise indicator, indicating exceedances of limit values, the number of persons exposed. Noise maps are not prescriptive. These are information documents that are not legally enforceable. As graphic elements, however, they can supplement a Local Planning Plan (LDP). As part of an Urban Travel Plan (UDP), maps can be used to establish baselines and target areas where better traffic management is needed. To quantify the level of noise emitted by an infrastructure over an average day, two indices are used, the Lden index and the Ln index, recommended for all modes of transport at European level: Lden: representative indicator of the average level over all 24 hours of the day, LN: representative indicator of the average sound level for the period 22h-6h. Noise levels are assessed using digital models (computer software) incorporating the main parameters that influence noise and its propagation (traffic data, field topology, meteorological data, etc.). The noise maps thus produced are then cross-checked with the demographic data of the areas concerned in order to make an estimate of the population exposed to noise pollution. The noise level shown on the noise maps is derived from a calculation method which gives approximate values and often higher than reality (maximists) in a noise area considered critical. An in situ noise control can determine precisely the noise to which a construction and its occupants may be exposed. The Lden limit values exceedance map (type C map) represents areas likely to contain residential, educational and health buildings where the limit values are exceeded in Lden in accordance with the prefectural sound classification decrees adopted pursuant to the Ministerial Decree of 30 May 1996 and based on a forecast evolution of traffic.欧盟2002/49/EC号环境噪声评估与管理指令（European Directive 2002/49/EC）旨在实现欧盟成员国范围内噪声暴露评估的统一化。该指令将噪声地图（noise maps）定义为基于噪声指标表征噪声状况、标明限值超标情况及受噪声暴露人群数量的数据形式。 噪声地图不具备强制性。此类文件仅为信息参考文档，不具备法律强制执行力，但作为可视化图形元素，可作为地方规划方案（Local Planning Plan, LDP）的补充材料。 作为城市交通规划（Urban Travel Plan, UDP）的组成部分，噪声地图可用于划定基准区域与需优化交通管理的重点管控区域。 为量化基础设施单日平均噪声排放水平，欧盟层面针对全交通类型推荐采用两类指标：Lden指数与Ln指数： Lden指数：代表全天24小时的等效平均噪声水平； Ln指数：代表22时至次日6时时段的夜间平均声级。 噪声水平评估依托融入噪声及其传播核心影响参数的数字模型（computer software）开展，相关参数涵盖交通数据、场地地形、气象数据等。 生成的噪声地图随后将与受影响区域的人口统计数据开展交叉核验，以估算受噪声污染暴露的人群规模。 噪声地图标注的噪声水平源自特定计算方法，该方法所得数值为近似值，在被认定为关键的噪声敏感区域中，结果往往高于实际监测值（即所谓的“乐观高估值”）。 现场噪声检测可精准测定建筑及其居住者实际暴露的噪声水平。 Lden限值超标地图（type C map，C型地图）用于标识存在住宅、教育及医疗建筑且Lden指标超出限值的区域，此类区域的划定依据1996年5月30日部长令颁布的县级噪声分类法令，并结合交通流量预测演化情况确定。