Ambient TSP concentration and dustfall in major cities of China: Spatial distribution and temporal variability

摘要

Based on environmental monitoring data in 93 major cities and meteorological records at 398 weather stations in China from 1981 to 2007, total suspended particle (TSP) concentration, the intensity of dustfall, and sand and dust storm frequency (F_d) were analysed. During the past 27 years, the annual average TSP concentration (C_(TSP)) in 93 cities was 402 μg m~(-3). Annual average C_(TSP) decreased from the north to the south and from inland to the coast areas with a peak value of 628.8 μg m~(-3) in Lanzhou. In the 1980s, 1990s and 2000s, annual average C_(TSP) was 628.7,319.2, and 250.1 μg m~(-3), respectively. Annual average intensity of dustfall (I_d) was 240.5 t km~(-2) a~(-1), decreased from northern to southern China and from inland to the coast areas with the maximum value of 717.2 t km~(-2) a~(-1) in Baotou. In the 1980s, 1990s and 2000s, annual average I_d was 334.8,220.9,1461 km~(-2) a~(-1) respectively. Annual average I_d in the Loess Plateau region was commonly higher than 200 t km~(-2) a~(-1). The annual average F_d decreased from arid regions in northwestern China to humid areas in southeastern China with two sand and sand storm centers existing in Xinjiang Taklamakan Desert and western Inner Mongolia. The annual average F_d in the 1980s, 1990s, 2000s was 16, 8, 6 days respectively, decreased steadily from 18 days in 1981-5 days in 2007. Annual average I_d had a positive linear relation to annual average C_(TSP) (R~2 = 0.96). Annual average F_d had a positive relation with annual average C_(TSP) (R~2 = 0.97) as well as annual average I_d (R~2 = 0.94). TSP was the chief pollutant influencing Air Pollution Index (API) in northern China in spring and winter seasons. Sand and dust storm might be a major factor affecting the temporal variability and spatial distribution of TSP and dustfall in China.