Water Erosion (english version)

Soil Erosion: Causes and Consequences

Overview of Soil Erosion

• Each year, billions of tons of soil are lost in the U.S. due to erosion, which diminishes soil productivity and deteriorates water quality.

• Severe erosion can render land unproductive, leading to abandonment as it removes topsoil first, exposing less productive subsoil.

Forces Behind Soil Erosion

• Soil erosion is primarily caused by two natural forces: wind and water. Wind can significantly increase soil loss on bare fields as speeds rise.

• Water erosion starts with raindrops striking the ground at high speeds (up to 30 mph), dislodging soil particles that can be splashed several feet away.

Types of Water Erosion

• Water erosion is classified into five types: sheet, rill, ephemeral, gully, and streambank erosion.

• Sheet Erosion: Involves gradual loss of thin layers of topsoil across a field; often goes unnoticed until significant damage occurs.

• Rill Erosion: Identified by small channels or rills forming in bare soil; these can be removed through normal tillage.

Ephemeral and Gully Erosion

• Ephemeral erosion forms in consistent locations each year within natural depressions where water flows concentrate; it can also be managed with tillage.

• Gully erosion creates large channels that cannot be erased by ordinary tillage; unchecked gullies threaten farmland sustainability and limit machinery access.

Streambank Erosion

• Streambank erosion results from continuous water flow cutting away banks; while generally slow, it accelerates during floods or heavy rains, potentially altering river courses.

Human Impact on Soil Erosion