TROPICAL GEOGRAPHY ›› 2016, Vol. 36 ›› Issue (4): 649-657.doi: 10.13284/j.cnki.rddl.002865

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Grain Size Characteristics and Sources Identification of Foliage Dust near Pedestrian Bridges in Guangzhou

ZHENG Yanming,LI Jiancheng   

  1. (Department of Geographic Sciences,Hanshan Normal University,Chaozhou 521041,China)
  • Received:2014-12-21 Online:2016-07-05 Published:2016-07-05

Abstract: Samples of urban dust deposited on leaf surfaces near 36 pedestrian bridges in Guangzhou in 2009 were measured to determine their grain size characteristics. The result revealed that the foliage dust was mainly composed of sandy silt, with silt volume content accounting for 53.99%, sand volume content for 41.34%, and clay volume content for 4.67%; Grain size frequency distribution showed three peaks, the main kurtosis lay between 10~200 μm. Grain size characteristics of the foliage dust in the 4 districts were very similar, that showed that as a whole of Guangzhou city, the causes and sources of the dust were relatively consistent. TSP (≤100 μm) content was high in the foliage dust, and PM2.5 and PM10 volume content slightly lower; the ratio of PM2.5 and PM10 was 0.36, indicating the pollution sources were presumably more from local road dust and construction dust. Moreover, study on aeolian dynamics of the foliage dust indicated that its source mainly came from suspended particulate matter within a short range of 30 km around the urban area, which belonged to the endogenous particles.

Key words: pedestrian bridges, foliage dust, grain size