Long-term monitoring of time-varying sound propagation from a large industrial area

A long-term monitoring project, with 12 months of continuous operation time, is described where the sound sources within a large industrial area as well as the sound levels in the nearby residential area are measured. The sources in the industrial area may give rise to complaints from the neighboring residential areas, at several kilometers distance. Especially sources that emit low frequency noise can contribute, depending on the meteorological conditions. This paper focusses on the model based long-term monitoring and the effects of the time varying sound propagation that is needed to determine the source strengths within the industrial area and the relevance of the sources for the nearby community. For this purpose data from a meteorological model is combined with measurements from multiple meteorological masts. The time-varying sound propagation for all possible sources is obtained near real-time. Besides the emission of the industrial sources, also the acoustic immission in the residential area is continuously measured by acoustic monitoring stations within the residential area. The calculated estimates of the immission are used to differentiate between the industrial related sounds and other sounds within the residential area. When considering possible noise nuisance due to the industry, the monitoring of other sounds should be excluded from the analysis. This differentiation is made by comparing the estimated immission with the measured sound levels in the residential area. It will be shown that this monitoring project captures the time-varying industrial noise as perceived in the residential area, whereas a standard noise model uses a constant sound propagation based on an average meteorology. © 2017 Institute of Noise Control Engineering. All rights reserved.
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