Impact action of soil particles on the crust in wind erosion

Wind erosion is the process by which the wind looses the soil, abrades the surface and removes soil particles from the surface, and is an essential process of soil desertification. Though soil particles being carried from the surface by wind is the final results of wind erosion, the abrasion of soil particles to the surface plays a major role in wind erosion. In this paper, we calculated the impact force of soil particles based on the 3D (three dimensional) saltating particle-crust collision model, which is different from the existing 2D (two dimensional) model. The results indicated that the angular velocities of soil particles make their lateral and horizontal impact forces on surface increase, so it makes the surface more fragile and easier to erode. The 2D grain-bed collision model could not describe the natural removal of soil particles by wind. Using the probability theory, we obtained the mean impact force and kinetic energy delivered to the crust per unit area per second., This can provide a theoretical prediction of a constant in the formula for wind erosion rate, such as the plastic pressure (Shao 2001), or for developing a new model using the mean impact force and delivery energy.