[Spatiotemporal dynamics of atmospheric PM 2.5 and PM 10 and its influencing factors in Nanchang, China].

PM _2.5 and PM ₁₀ have become the primary pollutants of most cities in China. Atmospheric PM _2.5 and PM ₁₀ mass concentrations, meteorological factors, traffic flow from 2013 to 2015 in Nanchang were analyzed. Spatiotemporal dynamic pattern of atmospheric particulate matter pollution and the effect of weather and traffic on particle concentration change were discussed in this paper. The results showed that PM _2.5 (70.92 μg·m ^-3 in 2013 > 53.70 μg·m ^-3 in 2014 ＞ 43.65 μg·m ^-3 in 2015) and PM ₁₀ (119.72 μg·m ^-3 in 2013 ＞ 86.11 μg·m ^-3 in 2014 ＞ 73.32 μg·m ^-3 in 2015) concentrations decreased gradually from 2013 to 2015. In addition, low concentrations of PM _2.5 and PM ₁₀ in summer (average PM _2.5 concentration 36.74 μg·m ^-3 , average PM ₁₀ concentration 69.20 μg·m ^-3 ) but high concentrations in winter (average PM _2.5 concentration 74.29 μg·m ^-3 , average PM ₁₀ concentration 111.64 μg·m ^-3 ) were observed. Moreover, PM _2.5 and PM ₁₀ concentrations changed with the urban-rural gradient, decreasing from the city center to suburb. The ratio of PM _2.5 /PM ₁₀ (0.595 ＞ 0.584 ＞ 0.557) decreased year by year from 2013 to 2015 and was higher in the city center area than in the edge of city. PM _2.5 and PM ₁₀ concentrations were affected by various meteorological factors and significantly related to air pressure, temperature, relative humidity, wind speed, precipitation and sunshine time. The influence of meteorological factors differed on PM _2.5 and PM ₁₀ concentrations. Traffic flow significantly increased the surrounding PM _2.5 concentration, but not PM ₁₀ concentration.