Effects of dust emissions from wind erosion of soil on ambient air quality

Wind erosion of soil is one of the most important sources of atmospheric particulate matter (PM). Determining the contribution of wind erosion of soil to the concentration of atmospheric PM is essential for the formulation of management strategies. In this study, we determined the contribution values (CVs) which denote the contribution of dust emissions to PM2.5 or PM10 levels, and the sharing rates (SRs) which denote the proportion of PM2.5 and PM10 emissions from soil to atmosphere in Ningxia, located in the upper arms of the Yellow River in western China. The results showed that, at a spatial scale, except in the summer, the CVs and SRs followed the order Guyuan > Yinchuan > Shizuishan > Zhongwei > Wuzhong, and the impact of wind erosion of soil on ambient air quality in Guyuan was higher than that in other cities; at a temporal scale, the CVs and SRs of dust emissions followed the order spring > winter > autumn > summer. The impact of wind erosion of soil on ambient air quality was highest in spring; the total PM2.5 and PM10 emissions were highest from cultivated land, followed by sandy land, grassland, forest land, and bare land. Our results are consistent with those obtained using chemical mass balance (CMB), which is the model for source apportionment of atmospheric PM (fitting verification R2 > 0.9), indicating that this approach can be used to estimate dust emissions due to wind erosion of soil on a large scale.