What are the four agents of erosion?
Wind, water, gravity, and ice
Water can erode soil material. Especially if the soil is bare, dry and erodable erosion via rain particles can occur.
Wind is another factor that cause soil erosion. Dry soil particles (especially if they are fine) can move to other areas if wind exists.
Ice is another issue on erosion. Ice, when it is melting, can carry soil particles.