Spatiotemporal Variation Characteristics of Evaluation on Meteorological Condition Index in Shaanxi
This paper used the actual monitoring data of PM2.5 concentration and evaluation on meteorological condition index(EMI)in Shaanxi province from 2015 to 2020,analyzed the spatial and temporal distribution characteristics of EMI in recent years,evaluated the impact of meteorological conditions change and control measures on Shaanxi ambient air quality.The results show that:From 2015 to 2020,EMI can characterize and evaluate the changes quite good in PM2.5 concentration caused by meteorological conditions.Since 2015,EMI showed a linear decreasing trend with the pickup of meteorological conditions.EMI was higher in winter than that in summer and it was high in Guanzhong region,followed by southern Shaanxi and northern Shaanxi,with the highest occurring in the central and western regions of Guanzhong region.According to the spatial distribution of meteorological conditions in winter,it was found that the regions with high positive EMI anomaly percentage concentration were in Guanzhong region.In the winter of 2016,the area of positively off level were 83.0%and positively offset by more than 100%were 37.5%in Guanzhong.Compared to the past five years,the PM25 concentration decreased by 24.8%,among them,the contribution rates of emission reduction and meteorological conditions respectively were 16.4%and 9.4%.It can be seen that the comprehensive control measures of air pollution in the province have achieved remarkable results in recent years,and the environmental quality has improved significantly.
Shaanxi provincefine particle PM2.5ambient air quality assessmentevaluation on meteorological condition indexcontribution rate