|ZHANG, XIAO-XIAO - Chinese Academy Of Sciences|
|CHEN, XI - Chinese Academy Of Sciences|
|WANG, ZI-FA - Chinese Academy Of Sciences|
Submitted to: Atmospheric Chemistry and Physics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2017
Publication Date: 2/3/2017
Citation: Zhang, X., Sharratt, B.S., Chen, X., Wang, Z. 2017. Dust deposition and ambient PM10 concentration in northwest China: Spatial and temporal variability. Atmospheric Chemistry and Physics. 17:1699-1711.
Interpretive Summary: Northwest China is one of the dustiest places on Earth. Atmospheric dust not only affects visibility and the welfare of plants and animals, but also public health. We found that southern Xinjiang Province in northwestern China has an annual PM10 (particulate matter less than or equal to 10 micron in diameter) concentration that exceeds national air quality standards. Elevated PM10 concentrations are caused by dust storms and is the major constituent of air pollution in the region. Severe air pollution caused by elevated PM10 concentrations occur on more than 20 days per year. Land management practices that minimize soil disturbance and retain vegetation on the surface will reduce wind erosion and improve air quality in the region.
Technical Abstract: Aeolian dust transport and deposition are important geophysical processes which influence global bio-geochemical cycles. Currently, reliable continental deposition data are scarce in central Asia. Located in the eastern part of central Asia, Xinjiang Province of northwestern China has long played a strategic role in cultural and economic trade between Asia and Europe. In this paper, we investigated the spatial-temporal variation in dust deposition from 2000 to 2013 and ambient particulate matter (PM10) concentration from 2005 to 2013 in Xinjiang Province. This variation was assessed using environmental monitoring records from 13 stations in the province. Over the 14 years, annual average dust deposition in the province ranged from 232.2 to 416.8 t•km-2. The annual average dust deposition was 147.8, 194.9 and 714.3 t•km-2 in northern, eastern and southern Xinjiang Province, respectively. Annual average PM10 concentration has increased from 99 to 141 µg•m-3 during the past 9 years and was 82, 118 and 192 µg•m-3 in northern, eastern and southern Xinjiang, respectively. The highest annual dust deposition and ambient PM10 concentration were observed in Hotan in the southern Taklamakan Desert with 1394.1 t•km-2 and 249 µg•m-3, respectively. Particulate matter was the chief air pollutant which significantly influenced regional air quality. Dust deposition was more intense during the spring and summer than other seasons. Annual average PM10 concentration had a positive logarithmic relation to dust deposition (R2 less than or equal to 0.86). The arid climate likely influenced the high dust deposition intensity and particulate matter concentration in the region. The annual average dust storm frequency increased during the past 14 years. There appeared to be was a positive relationship between dust storm days and dust deposition and airborne dust concentration in Xinjiang. This study suggests that sand storms are a major factor affecting the temporal variability and spatial distribution of dust deposition in central Asia.