Processes of Soil Erosion

| | | | | | | | | The Erosion Process1. Water. Erosion from water typically occurs in the following ways. a. Raindrop Splash and Sheet Erosion. The first step in the erosion process begins as raindrops impact the soil surface. Raindrops typically fall with a velocity of 20-30 feet per second. The energy of these impacts are sufficient to displace soil particles as high as two feet vertically. In addition, the impact of a rainfall on a bare soil can compact the upper layer of soil, creating a hard crust that inhibits plant establishment. Sheet erosion occurs as runoff travels over the ground, picking up and transporting the particles dislodged by raindrop impacts. The process of sheet erosion is uniform, gradual and difficult to detect until it develops into rill erosion. If runoff is maintained as sheet flow, the velocity remains low and there The method used to prevent erosion from raindrop splash and sheet erosion is stabilization. Stabilizing techniques such as temporary and permanent vegetation, sodding, mulching, compost blankets, and rolled erosion control products absorb the impact of raindrops and protect the ground surface. By protecting the surface, soil particles are not dislodged and transported by sheet flow. Typically, sheet flow does not have sufficient volume or velocity to dislodge soil particles from a bare surface by itself. It is dependant on raindrop impacts to disturb the surface. Therefore, stabilizing a surface, protects the ground from both raindrop and sheet erosion. b. Rill Erosion. Rill erosion occurs as runoff begins to form small concentrated channels. As rill erosion begins, erosion rates increase dramatically due to the resulting concentrated higher velocity flows. Construction sites that show signs of rill erosion need to be re-evaluated and additional erosion control techniques employed. Rilling can be repaired by tilling or discing and should be repaired as soon as possible in order to