云南省臭氧污染特征及气象影响分析

Analysis of Ozone Pollution Characteristics and Meteorological Impacts in Yunnan Province

为研究云南省臭氧(O3)污染特征及其与气象因子的关系,基于统计学方法及Arc GIS空间差异分析、线性趋势分析、空间离散系数等方法,对全省16个市(州) 2015—2017年33个环境监测站点的监测数据进行了研究。结果表明:研究期间,O3逐渐取代其他大气常规污染物成为首要污染物,其浓度变化范围为19~138μg/m^3。云南省各市(州) O3浓度年变化呈现周期性,月度峰值集中出现在春季(3—5月);日变化呈单峰形,峰值集中在14:00—17:00。O3浓度的空间格局由纵向集聚为主转变为横向集聚为主,各集聚区交错分布,低值区由西北部转移到西南部;O3浓度增长率为正的区域集中于东北部和中部,面积约为20.81万km^2,占全省总面积的54.29%,其余半环状区域增长率为负。迪庆州O3污染情况与其他市(州)明显不同,且受其他市(州)传输的影响较小。气象因子对O3浓度的影响随时间和地域条件的变化而变化,对典型市(州)(迪庆州、丽江市、昭通市) O3浓度影响最大的为偏南风,影响的浓度区间为20~160μg/m^3。

In order to study the characteristics of ozone pollution in Yunnan Province and its relationship with meteorological factors,based on statistical methods and Arc GIS spatial difference analysis,linear trend analysis and spatial dispersion coefficient,the data of 33 environmental monitoring stations in 16 cities of the province from 2015 to 2017 were studied. The results showed that O3 gradually replaced other atmospheric conventional pollutants as the primary pollutant during the study period,and its concentration ranged from 19 to 138 μg/m^3. The annual changes of O3 concentration in each city of Yunnan Province showed periodicity,and the monthly peak appeared in the spring( from March to May);the daily variation was unimodal,and the peak was concentrated at 14: 00-17: 00. O3 concentration spatial pattern changed from vertical agglomeration to horizontal agglomeration. The cluster areas were staggered and the low-value areas were transferred from the northwest to the southwest. The areas with positive growth rate of O3 concentration were concentrated in the northeast and in the central part,about 208 100 km^2,accounting for 54. 29% of the province total area,the remaining semi-ring areas had a negative growth rate. The O3 pollution situation in Diqing Prefecture was significantly different from that of other 15 cities,and was less affected by them. The influence of meteorological factors on O3 concentration varied with time and region. The most important influence on the concentration of O3 in typical cities( Diqing Prefecture,Lijiang City,Zhaotong City) were the southerly wind direction,which affected the concentration range from 20 to 160 μg/m^3.