Volume 16, No. 10, October 2016, Pages 2488-2511 PDF(13.63 MB)
Atmospheric PM2.5 Characteristics and Long-Term Trends in Tainan City, Southern Taiwan
Hung-Yi Lu1, John Kennedy Mwangi1, Lin-Chi Wang2, Yee-Lin Wu1, Chong-Yu Tseng1, Ken-Hui Chang3
1 Department of Environmental Engineering, National Cheng Kung University, Tainan City 70101, Taiwan
2 Department of Civil Engineering and Geomatics, Cheng Shiu University, Kaohsiung 833, Taiwan
3 Department of Safety, Health and Environmental Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan
- Ten year trends of PM2.5 and PM10 levels were investigated.
- Decennial trends indicate non-attainment of air quality standards.
- Model was used to investigate PM2.5 temporal and spatial distributions.
- Trans-boundary emissions are significant in the target city.
In order to analyze the characteristics and long-term trend levels of PM2.5 in Tainan City, Taiwan, Mesoscale Modeling System Generation 5 (MM5) and Community Multiscale Air Quality Model (MM5-CMAQ) modelling as well as box plots and time series analysis, were utilized in this study. The long-term trend analysis shows that the levels of PM2.5 (averaged at 38.3 µg m–3 and ranged between 33.1 and 41.9 µg m–3) in Tainan City for ten years (2005–2014) were above the yearly average standards of 15 µg m–3, showing non-attainment status. Overall, the results show a decreasing trend (from 41.9 µg m–3 in 2005 to 35.0 µg m–3 in 2014) in the levels of PM2.5 in Tainan atmosphere in the ten year period. The results of the MM5-CMAQ air quality modeling, indicate that the highest contribution on PM2.5 in Tainan City was from trans-boundary pollution from neighbouring cities (34.2%), while long-range transport and local emissions from Tainan each contributed a fraction of approximately 32.9%. In terms of local sources, the highest influence is from area sources (18.6%), followed by line sources (7.7%) and point sources (6.6%). Thus, to control PM2.5 in Tainan City, the focus should be on construction, road dust, and residential activities.
PM2.5; PM10; CMAQ; Air Quality; Modeling.