深圳市龙华新区PM2．5质量浓度分布特征及来源分析

通过对龙华新区2个监测站点2012年的PM2．5监测数据进行分析，得出新区PM2．5年均质量浓度值为0．043mg／m^3，全年总超标天数为30d，超标率为8．2％。PM2．5污染具有明显的季节性特征，干季污染严重，雨季则较轻。新区常年盛行偏北风，处于东莞、惠州等污染严重区域的下风向，且风速偏小，是新区PM2．5来源及质量浓度升高的重要原因之一。同时，利用大气环境影响评价系统的AERMOD模型对新区PM2，污染质量浓度分布进行模拟，结果显示新区PM2．5主要来自本地污染源，贡献率为51．2％，外地污染源贡献率为48．8％。其中，PM2．5污染主要受机动车尾气和道路扬尘影响，贡献率为32．0％，其次是施工项目和裸露土地影响，贡献率为18．2％，工业污染源影响非常小。

The Concentration Distribution and Sources of PM2.5 in Longhua District of Shenzhen

The analysis of PM2.5 monitoring data from Longhua District＇s two monitoring sites in 2012 shows that the PM2.5 pollution has obvious seasonal characteristics, and the PM2.5 pollution is more serious in the dry seasons than in the rainy seasons. Northerly winds are prevalent all year round in Longhua District, which is downwind of Dongguan and Huizhou, and the wind speed is relatively small, which also contributed to the high PM2.5 concentration. Meanwhile, the simulation result of Aermod System shows the contribution of local sources from Longhua District to the PM2.5 pollution is 51.2%, while the contribution of surrounding sources is 48.8%. Besides the PM2.5 concentration is influenced by motor vehicle exhaust and road dusts, at contribution rate of 32%, and the contribution of construction projects and bare land is 18.2%, while there is little pollution from industrial sources.