Irwin, Draxler and Taylor schemes are close to each other in magnitude while the
y values by Briggs and P–G schemes are approximately 1.5 to 2 times higher than
the rest of the schemes.A similar trend is observed in the case of stability B, though
themaximum variations are less pronounced here than in A. However, for stabilities
C and D all the schemes show comparable results. For stabilities E and F, again the
schemes based on Irwin, Draxler and Taylor’s formulations show similar results.
However there are slight variations on the high side by a factor of approximately
1.3 relative to the schemes based on Briggs and P–G formulations. These are more
significant close to the source, and as one approaches greater downwind distances
the variations become less pronounced.
The z values based on the Irwin and Draxler schemes show similar results in
the case of unstable conditions (i.e., stabilities A, B and C). The methods used by
these schemes are similar during these conditions. Tables IX–XIV do not report
z values based on the Taylor scheme as they were not available. As in the case
of y, the maximum variation among these schemes has been observed in the
case of stability A. The maximum z values are observed in the case of the P–G
scheme followed by the Briggs and Irwin schemes. Stability B also shows similar