2006~2019年珠三角地区臭氧污染趋势

Ozone Pollution Trend in the Pearl River Delta Region During 2006-2019

研究基于2006~2019年粤港澳珠江三角洲区域空气监测网络数据,利用Mann-Kendall检验法和Sen斜率法等统计方法计算了珠三角不同区域臭氧年际变化情况,并分析了变化的原因.结果表明:①2006~2019年珠三角平均臭氧浓度上升趋势显著(P<0.05),平均增长速率为0.80μg·(m^(3)·a)^(-1).2016年之后,臭氧平均增长速率为2.08μg·(m^(3)·a)^(-1),臭氧浓度增速加快.②珠三角臭氧浓度变化趋势有明显的空间差异和季节差异.中部地区臭氧年均浓度增加趋势显著,外围区域臭氧增加趋势不显著;臭氧增加趋势主要集中在夏季,其他季节变化趋势不显著.③珠三角臭氧变化趋势是由前体物和气象条件共同造成的,特别与NOx的浓度变化密切相关.2006~2019年珠三角中部区域NO2浓度明显下降,滴定效应减弱导致臭氧浓度增加;边缘地区NO2浓度变化较小,臭氧浓度未发生明显的改变.④随着前体物浓度的变化,珠三角臭氧生成敏感区的特征正在发生改变,VOCs控制区面积不断减少,协同控制区和NOx控制区面积逐渐增加,区域臭氧污染防治需要加强对前体物的协同控制.

Based on the monitoring data of the Guangdong-Hong Kong-Macao Pearl River Delta Regional(PRD)Air Quality Monitoring Network from 2006 to 2019,the ozone trend in RRD was analyzed using the Mann-Kendall test method,Sen's slope method,and the Pettitt change point test.The results show that:①the average ozone concentration in the PRD has increased significantly from 2006 to 2019(P<0.05),with an average growth rate of 0.80μg·(m^(3)·a)^(-1).After 2016,the rate of ozone increase has accelerated.②The average annual ozone concentration in the central PRD increased significantly,while in the peripheral areas of the PRD,this is not obvious.Ozone increases significantly in summer but not in other seasons.③From 2006 to 2019,the concentration of NO2 in the central PRD decreased remarkably,so the titration effect weakened and resulted in an increase in the ozone concentration.The concentration of NO2 in the marginal areas of the PRD has little change,so the ozone concentration in these areas has little change.④With the changes of VOCs and NO2 concentrations,the chemical sensitivity of O3 production in the PRD is changing.The VOC-limited regimes are continuously decreasing,and the mixed NOx-VOC-limited regimes and NOx-limited regimes are increasing.In order to deal with regional ozone pollution,the cooperative control of VOCs and NOx needs to strengthen.