Figure 1 - from "Comparative Study of Air Quality Models"

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lable 5.1 TSPM concentrations by plausibility approach model

Case-1 & Case-2 are nothing but two different assumptions of stability class occurrences. Case-1 is with the assumption of occurrence of stability classes as:- i) A class for 4 hours ii) B class for 4 hours iii) C class for 4 hours iv) D class for 12 hours and E & F class not occurring. Whereas, Case 2 is for real time occurrence of stability classes, for which 24-hour concentrations are maximum; computed by AERMOD. Meteorological conditions have studied for that day and used in the plausibility model. The occurrence of stability classes is as:- i) A class for 3 hours ii) B class for 3 hours iii) C class for 4 hours iv) D class for 12 hours v) E for 2 hours with no occurrence of F class. Figure 5.1 Comparison of Plausibility Approach Model results between case-1 and case-2

Comparative Study of Air Quality Models

Abstract: In mega cities and urban areas, industrial growth and vehicular emissions have caused severe concern of ambient air pollution. Situation is alarming; it can increase in near future to cope up with population expansion. Air quality models have been using for assessing impact of emission sources to ambient air pollution as well as for planning emission controls. These models use meteorology and emission inventory to trace the dispersion path of a pollutant to estimate the impact at the receptor. US-EPA's AERMOD has an improved approach for characterizing boundary layer parameters and vertical profile of atmosphere as compared to other dispersion models. The application of Gaussian Plume Model (GPM) requires knowledge of several parameters, i.e. atmospheric turbulence, emission release rate, wind speed, dispersion coefficients, effective stack height, mixing height etc. In most of the cases of Indian scenario, meteorological data is not available. Under such conditions, it is propo...

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