Abstract：Capable of spatial and temporal illustration, the grid-based air pollutant emission inventory was established in the Pearl River Delta (PRD) region in 2012 by calculating annual-total emission values and developing local spatial-temporal allocation schemes. The activity data of anthropogenic and natural sources were collected and applied to estimating multi-pollutant emissions by the “bottom-up” compilation approach. The annual estimated results show that the emissions of SO2, NOx, CO, PM10, PM2.5, VOCs and NH3 in the PRD region for the year of 2012 are 552kt, 1029kt, 3492kt, 952kt, 385kt, 1539kt and 177kt, respectively. Stationary combustion source is the largest SO2 and NOx contributors. Power plants and industrial boilers contribute 35.0% and 41.8% of SO2 emission, 28.2% and 16.2% of NOx emission. Processing source is the most significant VOCs emitters, and furniture manufacturing, oil refining and oil-gas port share 52.4% of total VOCs emissions. Fugitive dust, contributing 42.3% of PM2.5 emission, is one of the most important source of particulate matters. NH3 emission mainly comes from livestock feeding and fertilizer application, which occupy 50.7% and 26.8% of total regional NH3 emission. The emission results show remarkable variabilities over the PRD region spanning diurnal and seasonal time scales. A semi-annular high emission zone centralize along the “Dongguan-Guangzhou-Foshan” city cluster. Daytime (9:00 to 8:00pm) emission intensity is significantly higher than that of nighttime (9:00pm to 8:00am of next day). Summer and autumn are the slight higher emission seasons during the whole year.
