Soil Erosion

Soil erosion is the process by which the surface layers of soil are worn away by the action of wind, water, and ice. Erosion is initiated by drag, impact, or tractive forces acting on individual particles of soil at the surface.

Except for some cases of shoreline and stream channel erosion, natural soil erosion occurs at a relatively slow and steady rate. During times of human disturbances such as logging, mining, road building, or construction activities, soil can be left open and exposed and erosion can accelerate beyond the natural rate.

Two of the most common types of erosion are rainfall and wind erosion. When vegetation or cover is stripped away, surface soil is directly exposed to raindrops, runoff, and wind. It is a vicious cycle as the best solution is re-vegetation, yet continuing erosion jeopardizes re-vegetation.

The example below shows the results of revegetation.

Before

After

Mass Wasting

Mass wasting is the movement of soil and mineral earth, bedrock, or rock debris downslope in bulk, or as an intact mass, due to the pull of gravity and the interaction of erosive forces. Landslide is a general term for the slow to rapid descent of rock or soil.

Re-vegetation combined with cuttings can provide firm stabilization to slide or banks in danger of sliding. Inclusion of live cuttings can provide immediate structural value to a slope. The science of bioengineering is an integral part of rehabilitation of habitat.

Stream Bank and Stream Channel Erosion

Stream bank and channel erosion occurs when riparian vegetation is removed or disturbed or when the volume or velocity of flow in a stream is increased from natural or use-related processes.