Noise level Lden of railway axes in the major Walloon agglomerations - 2012 report

This data layer integrated into the 2012 European report locates the exposure to noise originating exclusively from railway routes according to the Lden index in the major Walloon agglomerations. The mapping of rail noise on the major Walloon agglomerations based on 2011 source data is the first achievement and, as it stands, the reference to this level. Noise maps have been reported to the European Environment Agency and are included in the 2012 report. The Lden index is one of the two indicators recommended by the European Directive 2002/49/EC, relating to the assessment and management of environmental noise, in order to measure the noise level describing environmental noise. Within the meaning of the Directive, the latter is emitted by means of transport, road, rail or air traffic or comes from sites of industrial activity. This data layer refers to the mapping of noise generated by rail routes crossing major Walloon agglomerations (Liège and Charleroi) in 2011 according to the Lden index. The Lden index stands for "Level Day - Evening - Night". It is therefore an indicator of the overall noise level for 24 hours (day, night and night) used to describe the discomfort associated with exposure to noise. It is calculated from the indicators "Lday", "Levening" and "Lnight", which are the average sound levels over the periods 7h-19h, 19h-23h and 23h-7h. Lden is expressed in decibel A (dB(A)), which is the unit used to represent the sensitivities of the human ear. In the Lden calculation, the ‘Levening’ and ‘Lnight’ indicators are weighted to take account of the fact that, at the same level, we are more sensitive to noise during these periods: - +5 dBA in the evening period, which means that a vehicle travelling in the evening is considered equivalent to almost three vehicles travelling during the day; - +10 dBA at night, which means that a vehicle travelling in the evening is considered equivalent to almost ten vehicles travelling during the day. According to the criteria defined for the mapping of noise emanating from railway axes in large agglomerations in 2011, the data layer covers all sections of railways crossing the territory of agglomerations of 100,000 inhabitants and more. In the Walloon region, these are the communal territories of Liège and Charleroi. Only these areas are covered by the mapping. The indicator is averaged over a calendar year. The data layer is therefore representative of a regional annual situation. It was drawn up on the basis of source data from 2011. Therefore, the data layers transcribe noise exposure to this period of time. The information was reported to the European Environment Agency in 2012 and is therefore included in the 2012 report. The data layer is a vector layer with, as an attribute, the value Lden. 5 exposure classes are selected: 55-59, 60-64, 65-69, 70-74 and greater than 75 dB(A). The low and high values of the exposure class concerned shall be recalled as an attribute.