Regional assessment for the occurrence probability of wind erosion based on the joint probability density function of air density and wind speed

The importance of air density variations in aeolian sand movement investigations is currently attracting widespread consideration. For this purpose, the spatial distribution characteristics of threshold wind velocity under the influence of air density are determined. To better understand the occurrence conditions of wind erosion events at different spatiotemporal scales, the present paper regards the air density metric as a bridge linking wind speed distribution and threshold wind velocity, reveals the coupling relationship between air density and wind speed by introducing the statistical distribution function method of probabilistic statistical thoughts, and accomplishes the scaling up of wind speed distribution parameters according to the random forest algorithm, achieving a comprehensive evaluation of the regional overall level of wind erosion events. The results demonstrate that the mean threshold wind velocity value in the study area is 4.29 m/s, displaying a decreasing pattern with higher values in the west and lower values in the east. The mean occurrence probability of the wind erosion value is 7.92 %, with regions exceeding 12 % basically located in the central and eastern parts of the Hunshandake Sandy Land, which means that the total annual cumulative time of wind erosion in these areas is expected to approach 1.5 months. This study can contribute to the development of a systematic assessment framework of wind erosion potential risks at the regional scale. It will provide crucial information and new insights for wind erosion process research, thereby offering a theoretical basis and technical reference for a full understanding of land desertification evolution patterns.