Aeolian desertification is a kind of land degradation that is characterized by aeolian activity, resulting from the responses of land ecosystems to climate change and anthropogenic disturbances. The source areas of the Yangtze and Yellow Rivers are typical regions of China’s Tibetan Plateau affected by aeolian desertification. We assessed the vulnerability of these areas to aeolian desertification by combining remote sensing with geographical information system technologies. We developed an assessment model with eight indicators, whose weights were determined by the analytical hierarchy process. Employing this model, we analyzed the spatial distribution of vulnerability to aeolian desertification and its changes from 2000 to 2010, and discuss the implications. Overall, low-vulnerability land was the most widespread, accounting for 64%, 62%, and 71% of the total study area in 2000, 2005, and 2010, respectively. The degree of vulnerability showed regional differences. In the source areas of the Yangtze River, land with high or very high vulnerability accounted for 17.4% of this sub-region in 2010, versus 2.6% in the source areas of the Yellow River. In the Zoige Basin, almost all of the land had very low to low vulnerability. To understand the change in vulnerability to aeolian desertification, we calculated an integrated vulnerability index (IVI). This analysis indicated that the vulnerability to aeolian desertification increased from 2000 to 2005 (IVI increased from 2.1709 to 2.2463), and decreased from 2005 to 2010 (IVI decreased from 2.2463 to 2.0057). Increasing regional temperatures appear to be primarily responsible for the change in vulnerability to aeolian desertification throughout the region. The effects of other factors (climatic variation and human activities) differed among the various sub-regions. The implementation of the ecological restoration project has achieved a noticeable effect since 2005. Our results provide empirical support for effort to protect the ecology of this ecologically fragile region.

The question of whether the emitted dust size distribution (EDSD) depends on wind velocity or soil size distribution (SSD) remains to be resolved. This study used wind tunnel tests to investigate the influence of wind velocity and SSD on EDSD. The results showed that EDSD was influenced by both wind velocity and soil texture, supporting the saltation bombardment theory. The ratios of PM_2.5to PM₁₀(R_PM2.5/10) and PM_1.0to PM₁₀(R_PM1.0/10), which reflect the EDSD in the range of 0–10 μm, both showed trends of increase with increasing friction velocity (u_*) for all six tested soils. The trend of increase was more significant forR_PM1.0/10than forR_PM2.5/10, which indicates that the content of finer dust in the range 0–10 μm increased with increasingu_*. Whenu_*increased from 0.51 to 0.68 m s⁻¹, the ranges of increase forR_PM2.5/10andR_PM1.0/10were most significant for sandy soils, followed by sandy loam soils and then loamy soils, indicating that the effect of wind velocity on EDSD increased with increasing sand content in the soils. The EDSD was also influenced significantly by the fully dispersed SSD, especially the sand and silt contents in the soils. TheR_PM2.5/10andR_PM1.0/10increased (decreased) logarithmically (linearly) with increasing sand (silt) content in these soils. The finding of this study represents enrichment of data regarding EDSD, which could lead to greater understanding of the roles of wind velocity and SSD in relation to EDSD.