A Gaussian model for estimating odour emissions from area sources

A Gaussian plume model for the dispersion of odours is modified to calculate the spatial average odour emissions from ground level area sources such as beef cattle feedlots, given simultaneous point measurements of odour concentration and wind speed at a location immediately downwind of the source. The validity of the method is demonstrated as is its application to sources of irregular shape, of finite lateral extent, and with wind directions other than perpendicular to the source. Source size, aerodynamic roughness of the surface and atmospheric stability are shown to be imporant in the selection of the preferred location for the measurements to enable a true spatial average emission rate to be calculated.