Development of a model of dispersion parameters for odour transmission from agricultural sources

A mathematical model of the dispersion parameters in the Gaussian plume model is developed for calculating ground-level odour concentration and for analysing the effect of wind speed on odour concentration. The model has three coefficients. The dispersion parameters are expressed as functions of downwind distance and wind speed, with wind speed being the most important factor to affect downwind concentration of odour from an agricultural source. The model was investigated by using the Pasquill-Gifford data. The range of downwind distances for which the model is applicable is from 100 to 1000 m, the zone of interest for odour dispersion from agricultural sources. The model is shown to fit the Pasquill-Gifford data effectively. The non-linear regression results also show that there is a dominant coefficient that determines the final estimation of the model. The error caused by incorporating the wind speed into the model is random. (C) 1998 Silsoe Research Institute.