Erosion is the removal and transport of soil by wind, water or mechanical means. Surface erosion is caused primarily by the action of raindrops and wind across the soil surface.
Raindrops are the primary agents of erosion.
They have high energy and initially start the erosion process by splashing and loosening soil particles. Surface erosion often occurs in range land and agricultural production areas where there is little or no vegetation. Gully erosion occurs in well defined channels. Gullies can be as shallow as a few inches or as deep as the Grand Canyon. Relatively clean water has a high capacity to transport sediments.