CUSTIC Algorithms I:
The mathematical model that the software uses provides options to model noise emissions from a wide range of sources that might be present at industrial areas and urban areas. The basis of the model is the linear sound propagation equation, which is used to model simple point source emissions from vehicles, industries, aircrafts,… Emission sources are categorized into two basic types of sources: point sources and line sources. The algorithms used to model each of these source types are described in detail in the following sections. The CUSTIC software accepts meteorological data records to define the conditions for sound propagation. The model estimates the noise level for each source and receptor combination and calculates user-selected averages.
For an external source, the noise level equation is
where r is the distance and LW the source power. However, for an industrial complex, the next equation will be used:
where S is the external surface and Li is the internal noise power.
Noise pollution map (colour gradient) produced by roads in decibels dB(A). The red colour represents high noise levels. We have 1000 vehicles per hour at a velocity of 50km/h.
Noise map for a road in ArcView that has been previously calculated by CUSTIC. The data have been exported in EXCEL and imported by ArcMap.
Noise map in the XZ plane for a line source. Colour gradient has been used.
Canarina Algoritmos Numéricos, S.L.
Environmental software solutions
Canary Islands, Spain
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