Combining a saltation impact sensor and a wind tunnel to explore wind erosion processes—A case study in the Zhundong mining area, Xinjiang, China

Abstract

The properties of surface soil determine its erodibility, the wind force determines the soil erosion intensity, and both factors determine the amount of soil erosion. In the Zhundong mining area in Xinjiang, China, continuous mining and construction activities in the past 10 years have resulted in the destruction of surface crust formed by precipitation, the gradual refinement of soil, and an increase in erodibility. To accurately describe the impact of human construction on local wind erosion, we installed a saltation impact sensor in a wind tunnel to explore the soil responses to wind erosion and changes in the wind erosion rate caused by anthropogenic interference. We artificially manipulated the soil moisture, crust coverage, and particle size, and subjected the soils to different wind speeds. The results show that, first, in soil crust and moisture experiments, a sensor can effectively monitor the process and amount of wind erosion, but the monitoring efficiency of the sensor is greatly reduced after an overall change in soil particle size. Second, the wind erosion processes in the three test groups are roughly the same: the wind starts to drive the soil particles to move for the first 0 to 30 s. Then, the number of released soil particles increases rapidly with increasing wind speed from 30 to 240 s, gradually decreases after the wind speed stabilizes from 240 to 480 s, and then remains consistent after 480 s. Third, a uniform distribution of the crust rather than a concentrated distribution of the crust can reduce soil erosion by 20%. The presence of a crust can effectively prevent erosion in the early stage of wind erosion, and the more complete the surface crust on the soil, the better it can resist continuous wind erosion. Fourth, moisture in the soil effectively impedes erosion by increasing the wind speed required to move particles in the early stage; however, continuous erosion decreases the soil moisture, and the proportion of eroded soil gradually increases in the later stage. Fifth, the erosion rate data show that particle size change can result in a maximum wind erosion rate of 2,599 g m^–2 min^–1 and is the most influential factor for wind erosion.