Map Viewing Service (WMS) of the dataset: Areas exposed to noise from the departmental road 648 west of Niort over 24 hours (Lden) in Deux-Sèvres

The European Directive on Strategic Noise Maps requires as a minimum the representation of the overall noise indicators Lden and Ln, for each source. These indicators correspond to the incident noise on the facades. The indicators represented are expressed in dB(A) and reflect a notion of overall discomfort or health risk. The data in this data set are related to the Lden indicator. “Lden" is an indicator of the overall noise level during a day (day, evening and night) used to qualify the discomfort associated with exposure to noise. It is calculated from the indicators "Lday", "Levening", "Lnight", "average noise levels over the periods 6h-18h, 18h-22h and 22h-6h. These are more precisely the isophone curves drawn in steps of 5 dB(A) from 55 dB(A) over a whole day. The data here concerns the Avenue de Nantes to the west of Niort. Articles L572-1 to 11 of the Environmental Code laying down various provisions for adaptation to Community law in the field of the environment and the implementing texts (Decree No 2006-361 of 24 March 2006, Decree of 4 April 2006 and Circular of 7 June 2007 on the drawing up of noise maps and plans for the prevention of environmental noise) provide for the indicators, the calculation methods to be used and the results I'm waiting for you. The data for this lot have been collected in accordance with these texts.《欧洲战略噪声地图指令》（European Directive on Strategic Noise Maps）要求至少需针对各噪声源，呈现整体噪声指标Lden与Ln。上述指标对应建筑外立面所承受的入射噪声，以dB(A)为计量单位，可反映噪声引发的整体不适或健康风险相关概念。 本数据集的数据均与Lden指标相关。Lden是用于表征全日（昼间、傍晚与夜间）整体噪声水平的指标，用以衡量噪声暴露所引发的不适程度。其计算基于Lday、Levening、Lnight三个时段指标，即6时至18时、18时至22时以及22时至6时三个时间段的平均噪声水平。 此处更具体地指以5 dB(A)为间隔、从55 dB(A)起始绘制的全日等声级曲线（isophone curves）。本次数据集的数据覆盖法国尼奥尔特（Niort）西侧的南特大道（Avenue de Nantes）。 《环境法典》第L572-1条至第L572-11条，以及为适配欧盟环境领域法律而制定的各项条款与相关实施文本（2006年3月24日第2006-361号法令、2006年4月4日法令及2007年6月7日关于编制噪声地图与环境噪声防治方案的通告），明确了需采用的噪声指标、计算方法及最终结果要求。本批次数据均严格按照上述法规文本采集完成。