Estimation of atmospheric dilution factors for trombay site using the air pollution model

This paper presents the application of The Air Pollution Model (TAPM) in estimation of atmospheric dilution factors for Trombay site for unit release rate in different wind sectors. The values obtained from the model are compared with those obtained from routinely collected meteorological data at 10 m height. The measurement carried out at 10 m height is extrapolated to the release height using power laws with stability-dependent coefficient. The maximum value of dilution factor at 1.6 km, computed using model data is 0.1039E-06 s/m 3 while that obtained using measured data is 0.1238E-06 s/m 3 ; however, the two are occurring in different sectors. Thus, model-generated dilution factors can be used in case if only the maximum impact of the releases need to be studied and no measured data are available. In general, it was found that except few sectors, model-generated dilution factors remain within a factor of two as compared to that generated using measured data. The main application of this study is for upcoming sites where representative measured meteorological data may not be available; however, computation of atmospheric dilution factors is required for environmental impact assessment.