Spatial-temporal evaluation of PM2.5 concentration for health risk reduction strategy development in a basin with different weather patterns

Identifying the contribution of pollution sources to the atmospheric environment is critical to make an effective pollution reduction strategy for controlling the regional air quality. Spatial-temporal distribution of pollutant patterns is not only determined by the emission rate of a pollution source, but also closely related to the location of an emission source, regional topography, and wind field conditions. To understand the spatial pattern of pollutants under different weather conditions and topographical factors, this study evaluated the impact of largescale stationary pollution sources in Taichung Basin located in Central Taiwan on regional air quality using The Air Pollution Model (TAPM), in which different weather types were taken into considerations. Results show that the present TAPM model could accurately simulate 44.0-95.0% of 5 actual synoptic weather conditions, including Outer-region circulation from tropical depression system, Weak northeast monsoon, Anticyclonic Outflow, The westward extension of Pacific Anticyclone, and South-deflected airflow. The research results revealed that weather types and regional wind fields dominated the pollutant transport patterns, where the westward extension of the Pacific Anticyclone and South-deflected Airflow could deteriorate the convection diffusive conditions, causing high pollution events for Taichung Basin. Based on the present results, the air pollutants transport patterns under different synoptic weather conditions could be used as practical information by decision-makers to develop efficient air quality control strategies in the future.