Author(s): Salomons Erik, Eisses Arno
An important element of the new EU model for environmental noise, Cnossos-EU, is the sound propagation model. The effect of meteorology on sound propagation is taken into account with Cnossos through a distinction between two meteorological states: favourable and homogeneous. Long-term average sound levels are calculated by weighted summation of sound levels for the two states, using the statistical fraction of the state favourable as a model parameter. We have calculated values of this parameter for The Netherlands. The effect of the asymmetric wind rose is taken into account, as well as the difference between day and night. We have also performed various test calculations with the Cnossos model and compared the results with results of the current Dutch calculation methods for traffic noise and industry noise. From these test calculations, a number of issues with the Cnossos propagation model have emerged. The issues include both real problems of the model and unclarities in the textual description of the model. Recommendations are given for solving the issues and thereby improving the Cnossos model.
Name: Dr Erik Salomons