“…Uncertainties in the use of the standard PG curves in rough terrain have promoted a number of field measurement programs for obtaining data on the variation of pollutant concentrations, 0y(x) and 0z(x) with distance for a variety of landforms. Shearer and Minott (1976), Shearer, Minott, and Hilst (1977). , Marker (1977), Draxler (1979) have summarized several of these studies (see Appendix IV for a number of these special diffusion experiments for different landforms).…”