Map Viewing Service (WMS) of the dataset: Noise zones related to major road infrastructure — Map of type a — Lden index (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: road map type a 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本数据集汇总了依据2006年3月24日法令第3-II-1°-b条编制的战略噪声地图（strategic noise maps）通用表格，适用于基础设施场景，所涉基础设施类型为a类道路地图与Lden指数。 噪声级分区（noise level zones）基于噪声指标或受噪声影响的区域，描述噪声暴露状况，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（或称a类地图）以每5dB(A)为一档绘制等声级线（isophone curves）。受噪声影响区域地图（或称"b类地图"）由省省长政令划定。限值超标地图（c类地图）则标注出制图年度内Lden指数与Ln指数超出限值的区域，其中Lden指数为24小时等效声级，Ln指数为22时至6时夜间时段的噪声级。 按基础设施分类的数据来源：CEREMA、ASF