Summary
How have the maps been produced?
The maps were created using specialised noise modelling software, which calculates the noise level on a 10m grid at a reception height of 4m above local ground level as required by the Regulations. The data required for the calculations of noise levels have been determined by consultation with various organisations including Transport Scotland, SEPA, Network Rail, Airport Operators, Local Authorities, and others. The software takes account of physical features such as buildings and the ground contours. The grid information is then used to create the series of noise contours bands as shown in the noise maps.
Strategic noise maps have been produced using the European Commission’s common noise assessment methods (CNOSSOS-EU). This is a new method of producing strategic noise maps for the entirety of Scotland, meaning the previous three rounds are not comparable to this round. CNOSSOS sets out three main aspects of its modelling method:
- Source part: The noise source emission describes the sound power emitted by the source of a variety of factors. For example, in the case of road traffic, this would include traffic volume and speed, road temperature, road gradient and road surface
- Propagation part: Propagation defines how noise levels attenuate/reduce due to aspects such as the distance along a propagation path (source to receiver), air absorption, terrain elevation, screening effects from buildings and barriers, meteorological effects and the influence of ground cover
- Receiver part: The receiver part specifies how receiver points should be positioned on dwelling facades, how the number of people and dwellings should be attributed to the noise exposures calculated at the facade receivers and how the area exposed to the noise should be determined from the calculated noise grids
The analysis was completed using several in house, open source, and commercially available software tools, and was delivered by Noise Consultants Limited, acting on behalf of the Scottish Government.