Erosion

In arid areas where vegetation is sparse, heavy rainfall can cause flash flooding. Runoff after a storm in the lower Park Avenue area of Arches National Park, Utah.

NPS photo.

When a rock particle (loosened by one of the two weathering processes) is moved by some flowing agent such as air, water or ice the process is called erosion.

Glacier Ice

Flowing Water

Rivers and Streams

Alluvium

Sand, gravel, and silt deposited by rivers and streams in a valley bottom.

Alluvial Fan

A fan-shaped pile of sediment that forms where a rapidly flowing mountain stream enters a relatively flat valley. As water slows down, it deposits sediment (alluvium) that gradually builds a fan.

• River Systems and Fluvial Landforms

Coastal and Shorline Processes

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  Shoreline Weathering
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  Coastal Erosion
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  Sediment Transport and Deposition

Wind

Aeolian is the technical term for wind-driven erosion and transportation, wind-blown sediment (such as sand and silt), and wind generated deposits (such as sand dunes).

• Aeolian Landforms and Processes
• Geological Monitoring of Aeolian Features and Processes