data download service (WFS) from: Railways, noise chart type “a” index Ln (night)

Strategic noise maps, in accordance with European Directive 2002/49/EC of 25 June 2002, allow for the overall assessment of exposure to noise in the environment. They allow a representation of noise levels, but also to enumerate the exposed population, quantify the nuisances, and then draw up action plans. The type “a” map locates the noise-exposed areas using Ln (Level night) isophones in steps from 5 in 5 from 50 dB(A) to more than 70 dB(A). The Ln (Level night) is an indication of noise discomfort. DB(A) is a unit of measurement expressing a level of intensity (decibel) weighted according to the physiological characteristics of the human ear. ___ Access to the municipality is available in the “Location” tab on the left of the map. Maximum consultation scale: 1/25 000 th ___ Only the documents annexed to the Orders are authentic ___ Card background: BD CARTO, SCAN 25, SCAN REGIONAL and SCAN 1000 ®© IGN C_045_570000_LNA_Values_Id C_045_569000_LNA_Values_Id C_N_COMMUNE_BDC_045 C_045_590000_LNA_Values_Id按照2002年6月25日颁布的欧盟指令2002/49/EC制作的战略噪声地图，可用于全面评估环境中的噪声暴露情况。此类地图不仅能够直观呈现噪声等级，还可统计受噪声影响的人口总量、量化噪声扰民程度，并据此制定噪声治理行动计划。 a型噪声地图采用夜间等效声级（Level night, Ln）的等声级线（isophones）划定噪声暴露区域，等声级间隔为5 dB(A)，覆盖区间从50 dB(A)至70 dB(A)以上。夜间等效声级（Ln）是衡量噪声扰民程度的参考指标，而dB(A)则是依据人耳生理特性加权的声强（分贝）计量单位。 可通过地图左侧的「位置」标签页查看所属市镇的相关信息。 最大浏览比例尺：1/25000 仅附于正式政令后的相关文件方为官方有效版本 地图底图数据源自BD CARTO、SCAN 25、SCAN REGIONAL及SCAN 1000 ®© 法国国家地理研究院（Institut Géographique National, IGN） C_045_570000_LNA_Values_Id C_045_569000_LNA_Values_Id C_N_COMMUNE_BDC_045 C_045_590000_LNA_Values_Id