Abstract
A method is presented for estimating the area enclosed by an isopleth of dosage downwind of a point source in the atmosphere. The method employs an empirical relationship between the area enclosed by a dosage isopleth and the value of the the isopleth divided by the source strength and multiplied by wind speed. The relationship is classified according to atmospheric stability. Comparisons are made between results obtained over short grass (O'Neill, Nebraska) and arid sagebrush vegetation (Hanford, Washington).