November 2004 (PDF 11.6 MB) - Barrick Gold Corporation

Figure 1.5.Assessing the likelihood of wind and temperature inversionsenhancing noise impacts at a siteConsider wind and temperature inversions(Section 5)Do initial screening testAssume specified default values for wind (Section 5.3.2)and temperature inversions (Section 5.2) in the predictionof noise levels from the source.Noise impactpredicted?NoNo further consideration ofweather conditions requiredTemperature inversionsYesWindDetermine percentage occurrence of temperatureinversions (Section 5.2 & Appendix C)Based on existing data (Bureau of Meteorology)or site measurementsDeterminepercentage of timethe wind direction isfrom source toreceiverIs this > 30% of thetime at night 1 in winter?(Section 5.2)NoIs this > 30% of the time inany period and season?(Section 5.3.1)YesNo further consideration of windand/or temperature inversions neededYesTemperature inversions and associateddrainage wind are a site featureNoise predictions should take account of temperatureinversions using either default inversion values specified inSection 5.2 or measured site-specific dataWind is a site featureNoise predictions should take account ofwind using wind speeds specified inSection 5.3.2 or measured site-specific data1For the purpose of determining the frequency of inversions, night is defined as the period from 1 hour beforesunset to 1 hour after sunrise, taken to be 6 pm to 7 am.NSW industrial noise policy12