Differences in the Effect of Sanding Wind Speed Thresholds on Wind Erosion Assessment Results

Abstract

Soil wind erosion is an important cause of topsoil loss in arid and semi-arid areas of China, and the estimation of wind erosion is related to meteorology, topography, soil, vegetation and other factors, and the threshold value of sand initiation wind speed directly affects the results of wind erosion assessment. Qinghai Province as a key area of wind and sand prevention and control, assessment of wind erosion is significant, this paper corrects the sand threshold of wind factor, comparing the unique value of 5.5 mꞏs-1 and the distributed threshold calculated by the formula method, respectively, to participate in the calculation of the amount of wind erosion. The results show that: when the threshold value of 5.5 mꞏs-1 is taken, the wind erosion modulus in 2020 is 34.11 tꞏhm-2ꞏa-1, and the erosion amount is 1.175 billion t. When the threshold value is calculated using the distributed threshold of the formula method, the wind erosion modulus is 58.79 tꞏhm-2ꞏa-1, and the erosion amount is 2.933 billion t. The formula method is a combination of soil particle size, soil moisture and vegetation cover to obtain the critical sand-generating wind speed, which is more accurate in the Qaidam basin and Gonghe basin. The results show that the average soil wind erosion intensity in Qinghai Province is intensity erosion, and the spatial wind erosion intensity is higher in Qaidam Basin, Gonghe Basin and the western region of Sanjiangyuan, while the erosion is weaker in eastern and southeastern Qinghai. Wind erosion occurs mostly in winter and spring.