陕西区域环境空气质量时空特征
张佳音, 郭云飞, 肖舜, 杜涛, 郑淏, 刘焕武, 王蕾, 何延新

The temporal and spatial characteristics of ambient air quality in Shaanxi
Jiayin Zhang, Yunfei Guo, Shun Xiao, Tao Du, Hao Zheng, Huanwu Liu, Lei Wang, Yanxin He
图4 2017—2021年陕西不同区域累计重度及以上污染天数及首要污染物占比
Fig.4 Cumulative days of severe and above pollution and the proportion of primary pollutants in different regions of Shaanxi during 2017-2021