Field Observation on Variation of Dust Emission Efficiency With Wind Velocity and Dynamic Properties of Soil in Sandy Loam Farmland

Abstract Dust emission efficiency ( E d ), as a key parameter in dust emission models has attracted increasing attention in recent years, but little is known about its dynamic variation in the field. Through field observation, this study analyzed four severe wind erosion events (WEEs) in different years that occurred on the same sandy loam farmland in the Bashang area (Hebei Province, China). Specifically, changes in horizontal saltation flux ( Q s ), PM 10 vertical flux ( F v ), and E d with wind friction velocity ( u * ) and dynamic properties of soil were investigated. Results show that Q s and F v both exhibit a strong synchronous trend with u * , but the changing trend in E d over time among different WEEs is very different and not necessarily related to the changing trend in u * . E d generally shows a trend of reduction with increasing u * , which may indicate that the supply of dust on sandy loam farmland surface is limited. There is a substantial difference in Q s , F v , and E d for different WEEs. This can be attributed to differences in the dynamic properties of the surface soil, especially the particle size distribution of soil aggregates and surface roughness. The findings of this study on sandy loam farmland surface indicate that E d for a certain location in the field may vary continuously with change in wind and soil conditions. Therefore, it is urgent to strengthen the research on the dynamic variation of E d with changes in wind and soil conditions.