Desert steppe is widely distributed in wind erosion regions, and is also an important potential dust emission source in the regions. Recognition of dust emission characteristics of desert steppe is the foundation for accurate simulation of dust emission in wind erosion regions; however, few related studies have been conducted in desert steppe areas. In this study, we selected four sites in a region of desert steppe to conducting dust emission observations, analyzing the characteristics of horizontal saltation flux and vertical dust flux, identifying the suitable models for desert steppe, and examining the relationship between saltation bombardment efficiency and wind friction speed (). The results revealed the following: the supply of saltation particles in most desert steppe is unlimited, the intensity of saltation is reasonably high, and the modified Owen-type model is suitable for predicting sediment transport above desert steppe. Dust emission intensity in desert steppe is lower than that in other land use types under similar wind speeds. Schemes based on saltation bombardment theory (i.e., the MB95, Shao93, and Kok12 schemes) were found suitable for predicting vertical dust flux above desert steppe, the Kok12 dust emission scheme performed slightly better than the other two schemes. Saltation bombardment is the main mechanism for dust emission when exceeds a threshold (), but aerodynamic entrainment also plays an important role in dust emission, especially when < . The saltation bombardment efficiency of desert steppe is less than that of other land use types. The trend of change in saltation bombardment efficiency with wind speed varies at different sites. Soil properties affect the dependence of saltation bombardment efficiency on . Desert steppe is an important dust emission source in certain regions, and improved understanding of dust emission in desert steppe areas is required.

中文翻译：

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荒漠草原扬尘特征


荒漠草原广泛分布于风蚀区，也是该地区重要的潜在沙尘排放源。认识荒漠草原沙尘排放特征是精确模拟风蚀区沙尘排放的基础；然而，在荒漠草原地区开展的相关研究却很少。本研究选取荒漠草原地区的4个站点进行沙尘排放观测，分析水平跃迁通量和垂直沙尘通量特征，确定适合荒漠草原的模型，并考察跃迁轰击效率与风的关系。摩擦速度（）。结果表明：大多数荒漠草原的跃移颗粒供给量是无限的，跃移强度相当高，修正的Owen型模型适合预测荒漠草原上空的泥沙输运。相似风速下荒漠草原扬尘强度低于其他土地利用类型。基于跃移轰击理论的方案（即MB95、Shao93和Kok12方案）适合预测荒漠草原上空的垂直沙尘通量，Kok12沙尘排放方案的表现略优于其他两个方案。当超过阈值（ ）时，跃动轰击是粉尘排放的主要机制，但空气动力夹带在粉尘排放中也起着重要作用，特别是当< 时。荒漠草原的跃迁轰击效率低于其他土地利用类型。不同地点跃变轰击效率随风速的变化趋势不同。土壤特性影响跃动轰击效率对 的依赖性。 荒漠草原是部分地区重要的沙尘排放源，需要提高对荒漠草原地区沙尘排放的认识。