Volume 14, No. 3, April 2014, Pages 829-839 PDF(1005 KB)
Effects of Particulate Matter of Various Sizes Derived from Suburban Farmland, Woodland and Grassland on Air Quality of the Central District in Tianjin, China
Li Chen1,2, Jincheng Gao3, Yaqin Ji4, Zhipeng Bai1, Mengshuang Shi2, Hui Liu2
1 Chinese Research Academy of Environmental Science, Beijing 100012, China
2 College of Urban and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
3 Department of Agronomy, Kansas State University, USA
4 China State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
Poor air quality directly affects human health and has become an increasingly important environmental issue in Tianjin, China. The suspension of particulate matter (PM) in the atmosphere is not only from industrial pollutants, but also soil wind erosion; however, the contributions from farmland, woodland, and grassland have rarely been considered in this region. We conducted an assessment of PM sources through wind erosion, dust emission, and dust transportation from urban and rural areas to the central district in Tianjin, and our results demonstrated that the spatial variability of wind erosion and dust emission strongly depends on land use, particle size distribution and meteorological conditions. The equations in this study were empirical, and soil properties such as aggregation and crusting, as well as surface characteristics such as canopy height and residue cover, were not considered. The dust emission capacity of woodland and grassland was the lowest because of vegetation coverage. The values obtained in this study may overestimate emissions, because soil aggregation was not considered. The yearly dust amounts of PM15–20 (particles with aerodynamic diameter from 15 µm to 20 µm), PM10–15 (particles with aerodynamic diameter from 10 µm to 15 µm), and PM10 (particles with aerodynamic diameter less than 10 µm) from wind erosion in 2009 from the urban area in Tianjin were estimated as 5,400 t, 5700 t and 17,300 t, respectively, while those from the rural area were 14,000 t, 15,300 t and 40,700 t, respectively. The dust emission contributed from farmland accounted for 99.5%, and that from woodland and grassland only accounted for 0.5%. The PM10 transported to the central district and PM10 concentrations in the days with the 20% highest PM10 concentrations in the central district in 2009 were compared. The R2 was 0.74, which meant the two variables were highly correlated.
Wind erosion; Dust emission; Modeling; Particulate matter; GIS; Tianjin.