2006～2012年珠三角地区空气污染变化特征及影响因素

利用粤港珠江三角洲区域空气监控网络2006~2012年监测结果,分析了珠三角地区SO2、NO2、O3和PM10浓度的年、月变化及空间分布特征,并对产生时空分布变化的原因进行了剖析.结果表明:7年来,珠三角地区SO2、NO2和PM10浓度呈下降趋势,降幅分别为61.7%、17.4%和24.3%,O3浓度呈上升趋势,增幅为12.5%,总体而言,珠三角地区空气质量呈好转趋势;湿季(4~9月)空气质量明显优于干季(10月至翌年3月),各污染物浓度的月变化均呈双峰型,SO2、NO2和PM10峰值浓度出现在12月和3月,O3峰值浓度出现在10月和5月;SO2、NO2和PM10浓度高值区主要集中在中部的广佛地区,O3浓度在外围郊区呈现高值,各部分地区的污染物浓度变化趋势不一致,中部经济核心区一次污染物浓度下降趋势更为显著.珠三角地区空气质量的变化受多方面因素的影响,经济下行和政府治理是驱动一次污染逐年好转的主要因素,而政府对VOCs排放控制相对薄弱,VOCs排放与气候变化的共同作用可能是导致二次污染(尤其是O3污染)加剧的原因.

Variation characteristics and influencing factors of air pollution in Pearl River Delta area from 2006 to 2012

Observations of Pearl River Delta (PRD) regional air quality monitoring network during 2006-2012 were employed to capture the temporal and spatial variation characteristic of air pollution over PRD and then the causes of that were analyzed. Air quality had improved generally in PRD region as result of the decrease in SO2, NO2 and PM10 concentrations by 61.7%, 17.4% and 24.3% during 2006-2012, though 12.5% increase in O3 concentration in the same period. Air quality was better in wet season (April to September) than dry season (October to March), and the monthly-averaged concentrations of various pollutions were all bimodal, with peaks in December and March for SO2, NO2 and PM10 and October and May for O3. The high concentrations for SO2, NO2 and PM10 were mainly distributed in Foshan and Guangzhou but for O3 mainly in outside suburbs of PRD. The trends of concentration for different pollutants were not consistent in different regions of PRD. The central region of PRD had more significant decrease in primary pollutants, and those decreases were induced by many factors, especially in economic downturn and environmental protection policies. However, the relatively weaker control of VOCs, as well as climatic change, could intensify the secondary pollution particular in O3.