Validation of AERMOD prediction accuracy for particulate matters (PM10, PM2.5) for a large coal mine complex: A Multisource Perspective

Abstract

Particulate matter (PM) emission from coal mining activities is inevitable and a significant concern worldwide. American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) is one of the most widely used dispersion models for predicting air PM dispersion in coal mines. However, validation of AERMOD-predicted PM concentration in a large mine complex has not been reported. So, in this study, AERMOD predicted PM concentration was validated against the PM concentrations measured by nine continuous ambient air quality monitoring stations (CAAQMS) stationed in the Singrauli coal mining complex. The complex contains nine coal mines across 438 square kilometers, with around 129 pollution sources chiefly from the area, pit, and line categories. PM10 and PM2.5 concentrations peak during summer (204.58 µg/m3) and winter (67.67 µg/m3), respectively. The AERMOD model predicts peak dispersion of PM10 (500–1200 µg/m3) and PM2.5 (100–800 µg/m3) during the winter season. The AERMOD model reveals that the region's wind movement caused by land and lake breezes was the predominant driver of PM surface dispersion. In the winter season, atmospheric inversion increases ground-level PM concentrations in the region. The AERMOD cannot represent the vertical dispersion of PMs in the summer, resulting in an underestimation of PM concentration. The statistical validation shows that AERMOD underestimates PM10 and PM2.5 concentrations across all seasons and years. The AERMOD model's prediction accuracy for PM10 (R2 = 0.38) and PM2.5 (R2 = 0.56) is also low. Finally, it can be concluded that AERMOD-predicted PM concentrations are not accurate for large mining complexes but more suitable for individual mines.