[Localization of Soil Wind Erosion Dust Emission Factor in Beijing]

Soil wind erosion dust is one of the primary sources of fine particulate matter (PM_2.5). Compared with the fugitive dust emission inventory of typical domestic provinces and cities, we found that the maximum among the contribution rates of soil wind erosion dust to the local total fugitive dust PM_2.5 emission inventory was about 4 orders of magnitude higher than the minimum. This study provided a wind erosion equation and a determination method of parameter values. The remote sensing interpretation, China soil dataset, and meteorological data of each district in Beijing were used to achieve the spatial distribution of the vegetation coverage factor (V), soil erodibility index (I), and climatic factors (C) in the plain area of Beijing. This study also estimated the emission factor of soil wind erosion dust and its spatial distribution. The main conclusions are as follows: ① Taking 2017 and Beijing city as an example, it was found that the climatic factor (C) was underestimated to different extents by domestic scholars, and PM_2.5 emission factors were overestimated or underestimated. ② V, I, and C showed apparent spatial differences and the average values of them were 0.63±0.09, 188±73, and 0.029±0.009, respectively. The maximum values of V, I, and C were 1.5, 2.1, and 4.5 times the minimum among all districts, respectively. ③ The PM_2.5 emission factor of soil wind erosion dust in Beijing showed a high spatial distribution in the northwest and southeast. The average emission factor of the city was (0.0018±0.0008) t·(hm²·a)^-1, which is 0.54 times the highest emission factor (Xicheng District) and 3.12 times the lowest (Pinggu District). The area proportions of standardized emission factors with higher intensity (0.6 to 0.8] and high intensity (0.8 to 1.0] was 0.72% and 0.04%, respectively.