Rain, Rain, Don't let the Soil Wash Away!

What is an El Nino?

The term El Niño refers to the unusually warm surface water temperatures of the Pacific Ocean, off the coast of South America, and how the ocean and atmosphere interaction is affected. Approximately every seven years, the warm surface waters of the eastern Pacific Ocean cool and the cool surface waters of the western Pacific Ocean warm. This shift of warm water location pulls the jet-stream (which steers where storms travel) south to southern California and westward over Arizona and New Mexico.

Strong El Niños are associated with above-average precipitation in the southern parts of the United States from California to the Atlantic coast. The cloudier weather typically causes below-average winter temperatures for those states.

storm

Photo by Zooey, Flickr (CC BY-SA 2.0)

What is erosion?

Erosion is the action of surface processes, such as water flow or wind, that remove soil, rock, or dissolved material from one location on the Earth's crust, then transport it to another location.

How are an El Nino and erosion related?

Erosion is the action of surface processes, such as water flow or wind, that remove soil, rock, or dissolved material from one location on the Earth's crust, then transport it to another location.

 

Types of Water Erosion

 

Rainsplash Erosion

Rainsplash erosion occurs when rain moves soil particles directly. Rainsplash erosion typically occurs during intense rain events when a raindrop’s energy is able to detach and move soil particles.

 

 

 

sheet erosion

 

Photo by Mike Beauregard, Flickr (CC BY 2.0)

 

 

Rill Erosion

Rill erosion is characterized by shallow drainage channels less than 12 inches deep. Rills develop when surface waters concentrate in low points and erodes the soil. Rill erosion is common on bare land.

 

 

 

 

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Photo by Bethany Principe

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Photo by Mark Strobl, Flickr (CC BY 2.0)

 

 

 Sheet Erosion

Sheet erosion is the uniform removal of soil in thin layers by raindrop impact and shallow surface flow. Soil loss is gradual but the cumulative impact is large. Land with little to no vegetation is vulnerable to sheet erosion.  

 

 

 

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Photo by Vic Smothers

 

 

Gully Erosion

Gully erosion is characterized by drainage channels more than 12 inches deep. It occurs where surface water flow has become trapped in a small, concentrated stream and begins to erode channels in the ground surface.

How to Minimize Erosion

Plant vegetation, trees, ground cover, shrubs and other plants where the soil is vulnerable to erosion. Roots from these plants will help hold soil in place on the ground.

low water use landscape with mulch

Photo by Jackie Pascoe, Flickr (CC BY 2.0)

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Photo by Vic Smothers

Construct surface runoff barriers, such as edging made of bricks or stones, to help prevent soil erosion by minimizing runoff. If runoff is minimized, soil is less likely to be carried away by stormwater runoff.

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Photo by Vic Smothers

barrier in waterway

Photo by Vic Smothers

Apply mulch to retain moisture and also help prevent soil erosion.

mulch

Photo by Jodie Wilson, Flickr (CC BY 2.0)

shrubs and mulch

Photo by Dave Palmer, USACE, Flickr (CC BY-ND 2.0)