| چکیده انگلیسی مقاله |
Sediment caused by wind erosion worsens air quality and visibility, and its morphology is important in transport processes affecting adsorption equilibrium and the combined-state distribution of particles by influencing surface characteristics and interfacial interactions. In spite of intensified research during the last decades on wind erosion, there is knowledge gaps regarding the transport characteristics and morphology of wind erosion sediment. In view of this, we used passive collector and electron microscope tape to trap windblown sediment from of 0 to 60 cm height above ground for wind speeds of 8, 12, and 16 ms-1 in a wind tunnel test. Field emission scanning electron microscope (SU8010) was used to observe the morphology of wind erosion sediment from a Luvic cinnamon soil with a high erosion risk. The clay fraction is dominated by Vermiculite and Hydromica. The results show that (1) increasing wind speed leads to increase of soil loss, horizontal sediment flux, and particle size of wind eroded sediment; 2) the horizontal flux of wind eroded sediment decreases with increasing height, except for a wind speed of 8 ms-1; 3) the volume fraction of sediments with diameter less than 20 µm tends to increase with height. However, particles larger than 20 µm tend to decrease with height; 4) the shape of wind eroded sediment tends to have lower circularity, higher fractal dimension, and higher heterogeneity with the increase of particle size, which depends on the mineral composition. It can be concluded that the shape of wind eroded sediments at different wind speed depends on the particle size and abrasion by air flow, and the shape of wind erosion sediment at different transport height depends on particle size. |
