Noise zones linked to major railway infrastructure — Type c chart C index Lden (equivalent noise level over 24h) — departure from Tarn-et-Garonne

Aggregation of generic tables describing strategic noise maps pursuant to Article 3-II-1°-b of the Decree of 24 March 2006, for an infrastructure, type of infrastructure concerned: rail, type of card c and Lden index. Noise level zones describe a noise exposure situation based on a noise indicator or area affected by noise. They are used primarily for the preparation of strategic noise maps pursuant to Article R.572-5 of the Environmental Code. Noise exposure maps (or type a map) represent the isophone curves of 5 in 5 dB(A). The maps of the areas affected by noise (or “type b” maps) are defined by prefectural decrees. And limit value exceedance maps (type c map) represent for the mapping year the areas where the Lden and Ln limit values are exceeded (the Lden index (equivalent 24h sound level) and the Ln index (noise level over a night period from 22h to 6h)). Data source by infrastructure: CEREMA, ASF本数据集汇总了用于描述依据2006年3月24日法令第3-II-1°-b条所规定的战略噪声地图（strategic noise map）的通用表格，涵盖轨道交通类基础设施、c类地图以及Lden指数。 噪声级区域基于噪声指标或受噪声影响的范围，用以表征噪声暴露状况，其主要用于依据《环境法典》第R.572-5条编制战略噪声地图。 噪声暴露地图（即a类地图）展示每5dB(A)一档的等声级曲线（isophone curves）。受噪声影响区域地图（即"b类地图"）由省级政令（prefectural decrees）划定。而噪声限值超限地图（即c类地图）则展示制图年度内Lden指数（Lden）与Ln指数（Ln）超出限值的区域，其中Lden指数为等效24小时声级，Ln指数为22时至次日6时夜间时段的噪声级。本数据集按基础设施分类的数据源为CEREMA与ASF。