Dataset Direct Download Service (WFS): Areas exposed to noise on the Charente-Maritime (areas of type A — index of type LD) Prefectural decree n°18-1536 of 24 July 2018

Type A noise zones — LD type index. Layer produced by GIS workshop (April 2018) by compiling type A noise zones related to road infrastructure (CEEREMA report on "Strategic noise maps of the Charente-Maritime department (017) Major infrastructure not granted; Deadline 3: 2017-2022") and motorway ("Non-Technical Summary of the Sound Environment Mapping of the ASF Network on the Charente Maritime Department (17) in 2016") Noise zones are geometric elements of the strategic noise map. These maps also referred to as “type a maps” represent for the reference year in the form of isophone curves, the areas exposed to more than 55 dB(A) according to the Lden indicator (case of this geographical layer) and to more than 50 dB(A) according to the Ln indicator, with a step of 5 in 5 dB(A). The noise level on a noise map is represented on the basis of regulatory indicators: the “Ln” (Level night) and the “Lden” (Level day-evening-night) which are harmonised indicators at European level. The Ln is the average sound level for the night period (22h-6h). The Lden is the 24-hour weighted average sound level to account for the perceived discomfort with the same noise level, which is greater in the evening and at night compared to the day.