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abstract
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In preliminary modelling toward a noise map for Sydney, Ben Hinze created a model including 2m ground contours, road, rail and buildings. The geometry for road and rail lines was based on the centreline of these roads / rail with arbitrary values based on road or rail classification. Eg. 75 dB for freeways and stepping down in 5 dB increments for each drop in road classification. For buildings, the cadastral boundaries that were residential and created a polygon within a few meters or so away from the cadastral line. Then the 2011 Mesh Block and Census data were used. A population estimate was attached to each building based on the volume of the building (ie. building footprint area * the height), as to assign a greater number of people to larger, taller buildings (eg. unit blocks) compared to single dwellings. Then a noise level was calculated for each building for the road lines. These noise levels are based on the noise levels around each building facade and provide not only the maximum noise level at each building, but also an average and minimum noise levels around each building, acknowledging not everyone lives in the loudest room of each house. This data is a based on a crude model with the greatest limitation being the estimated building facade information based on block size and a nominal setback distance to define the footprint.
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