Map Viewing Service (WMS) of the dataset: Areas exposed to the noise of the departmental road 650 south 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 Saint-Jean d’Angély road south 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.《欧盟战略噪声地图指令》要求至少需针对各噪声源，展示总体噪声指标Lden与Ln。上述指标对应建筑外立面上的入射噪声，以dB(A)为单位，可用于表征总体不适或健康风险水平。 本数据集的数据均与Lden指标相关。 Lden是用于衡量全日（昼间、傍晚与夜间）整体噪声水平的指标，用以表征噪声暴露所引发的不适程度。该指标基于Lday、Levening与Lnight三个时段的平均噪声水平计算得出，对应时段分别为6时至18时、18时至22时以及22时至6时。 本数据集所呈现的具体内容为全日内以5 dB(A)为步长、从55 dB(A)起绘制的等声级线（isophone curves）。 本次数据集的数据取自尼奥尔特（Niort）南部的圣让当热利（Saint-Jean d’Angély）公路沿线。 《环境法典》（Environmental Code）第L572-1条至第L572-11条，以及为适配环境领域欧盟法律而制定的各类实施细则——包括2006年3月24日第2006-361号政令、2006年4月4日政令与2007年6月7日关于编制噪声地图及环境噪声防治方案的通告——均对上述噪声指标、所需采用的计算方法及最终成果作出了规定。 我在此等候您的指示。本批次数据均依照上述法规文件采集完成。