西安世园会园区大气环境质量与气象因子关系分析

Relationship Between Atmospheric Environmental Quality and Meteorological Factors in Spring and Summer During the Period of 2011 International Horticultural Exposition in Xi'an

分析了西安世园会召开期间春、夏季大气环境质量监测数据,发现PM10、NO2、SO2之间相关性较高,在短时间尺度上变化趋势一致,指示出较为单一的污染来源。利用同期获取的气象资料与PM10指数简单相关分析结果表明,春季风速愈大,大气PM10浓度愈高,而夏季风速较大有利于大气污染物扩散。气压、能见度、相对湿度在春季与PM10指数表现出较为显著的负相关性,与气温为明显的正相关关系。夏季只有风速和气温与PM10指数相关关系较为显著且变化趋势相反。最后综合春夏季6个气象因子与大气环境PM10指数偏相关分析的结果表明:相对湿度为首要控制因子;能见度呈较显著负相关性;由于春季大气环境监测资料较短,与风速总体呈弱负相关关系;研究时段内降水频次有限,对PM10浓度的抑制作用在统计意义上体现不明显;PM10与气温和气压的关系不显著。

The atmospheric environmental data monitored in spring and summer during the period of 2011 International Horticultural Exposition in Xi＇an were analyzed and results showed that PM10,NO2 and SO2 indices had uniform trends on short time scale with relatively high correlations among them,which indicated that they were from the same pollution sources.By analysis of the correlations between PM10 index and contemporary meteorological data,we found when wind speed was higher in spring,the concentration of PM10 was higher too;but in summer higher wind speed would lead to diffusion of atmospheric pollutants.In spring,there were significantly negative correlations between atmospheric pressure,visibility and relative humidity and PM10 index,but positive correlation for temperature.But in summer,only wind speed and temperature presented significant correlation but opposite trends with PM10 index.Detailed partial correlations between six meteorological factors in spring and summer and PM10 index indicated that relative humidity was the primary controlling factor and visibility presented significantly negative correlation,and wind speed showed generally weak correlation in spring probably due to short monitoring interval.It was not obvious in statistics that the inhibition of PM10 concentration because of limited precipitation frequencies during this period.And there were no significant correlations between PM10 index and temperature as well as pressure.