Comprehensive Effect of Soil Particle Size Composition and Wind Speed on Dust Emission Efficiency

Abstract

Recent studies have shown that the dust emission efficiency (Ed) of some soil surfaces undergoes changes with wind speed and that such changes are related to soil properties. Through wind tunnel experiments, we investigate the comprehensive effect of soil particle size composition (PSC) (both minimally and fully dispersed) and friction wind speed (u*) on Ed. Results show that Ed initially increases and then decreases as soil texture changes from fine to coarse, with intermediate‐textured soils having the highest Ed and the strongest dust emission ability. The ratio of silt to sand in soil is an index suitable for reflecting the influence of soil texture on Ed. The PSC of soil dry aggregate is a factor that directly determines Ed. With increasing u*, Ed tends to increase for coarse‐ and intermediate‐textured soils but not for fine‐textured soil, supporting the view that Ed is influenced by u* and that the influence is related to soil PSC. Despite the fitting power function equations between Ed and u* for some soils failing to pass the significance test in this study, the substantial influence of soil texture on the power exponents implies potential for establishing an equation capable of expressing the comprehensive effect of soil texture and u* on Ed.