近年来广州市环境空气质量变化趋势分析

Analysis of the urban environmental air quality and its trends in Guangzhou in recent years

利用广州市9个国控空气质量监测站及中山大学大气环境监测平台的监测数据,研究了广州市近年来常规污染物SO2、NO2、PM10及新标准增设指标PM2.5和O3的变化趋势。结果表明,近年来广州市常规污染物年度变化均呈现显著下降趋势,PM10季节性差异较大;从空间分布来看,城市中心区域NO2污染远高于非中心区域,但PM10和SO2的差异不明显。在新标准下,PM2.5质量浓度超标情况严重,但污染程度有所减轻;O3质量浓度日最大8 h平均超标率较O3质量浓度1 h平均超标率更高,且在夏秋两季更为明显。空气污染源增加产生的压力与环境保护措施的相互作用是驱动广州空气质量变化的主要因素。产业结构变化、清洁能源的使用及机动车尾气排放标准的提高等对提高空气质量起到了一定的作用。

This paper presents an analysis of the urban environmental air quality and its trends in Guangzhou in recent years. While doing our analysis, we have been attempting to quantify the changes of cri- teflon air-pollutant mass concentration basis for the last six years by using the Daniel method of trend test. In so doing, we have analyzed the testing results from the nine different monitoring stations in the city and compared the changing trends among the above said sites. All the data on the air quality pollutants in the city indicate a signifi- cant downward trend via our test with the Daniel method, though the seasonal examinations of the standard pollutants reveal a different pic- ture, in which the seasonal variation of SO2 and NO2 mass concentra- tions goes in a downward trend whereas the variation of the concentra- tions of PM10 goes upwards in spring and summer. Moreover, the concentration of PM10 has been found to change more significantly in seasonal variations than the other two pollutants. In addition, the analysis results from the various monitoring sites show that the pollu- tant mass concentration from each station varies in position and envi- ronment, with the concentration of NO2 in the urban centers being much higher than that away from the downtown areas, perhaps mainly due to the impact of heavy unban traffic and transportation. In accor- dance with the new standard, the emission of SO2 and PM10 is sup- posed to have already reached the stipulated standards, whereas the concentration of NO2 emission has to be decreased by another 19.9 % before reaching the new standards stipulated in the year of 2011. The new indicator of PM2.5 mass concentration proves to be excessively se- rious whereas the pollution degree has been reduced. Since the rate of the maximum eight-hour concentration of O3 exceeds the new standard more than the rate of average one-hour concentration of O3, which turns to be more serious during summer and fall. The interaction be- tween the intensified pressure of air pollution sources and the environ- mental protection measures that have been taken are the main factors leading to the changes of air quality in Guangzhou. And, as a result, the regulation of the industrial structure and the trend for application of clean energy sources and raising of the exhaust emission standard of the motor vehicles would surely play an important role in the protec- tion of air quality.