Diurnal and annual variation of the sensation distance of odour emitted bylivestock buildings calculated by the Austrian odour dispersion model (AODM)

The diurnal and annual variation of distances for different odour threshold s is investigated by the dynamic Austrian odour dispersion model (AODM) con sisting of an emission module, a dispersion module, and a module to calcula te instantaneous odour concentrations. The effect of daily variations in od our production, ventilation rates and indoor air temperature are included i n impact assessments. The ambient half-hour odour concentrations calculated by a regulatory Gaussian plume model are transformed to instantaneous valu es representative for the duration of a single breath by an attenuation fun ction decreasing the peak-to-mean ratio with increasing wind velocity, stab ility, and distance from the source. The resultant distances for different odour thresholds and their dependence on meteorological parameters are inve stigated and discussed in detail, focussing on the distance for the detecti on limit, 1 OU m(-3), the so-called sensation distance. The results suggest a stronger dependence of the sensation distance upon variation in meteorol ogical conditions than diurnal and annual variations in odour emission rate s. (C) 2000 Elsevier Science Ltd. All rights reserved.