Different Types of Soil Erosion and How to Prevent It
Soil erosion is a natural process that involves the movement of soil particles from one place to another. However, because of human activity, erosion has become a major problem affecting soil fertility, agricultural productivity, and water quality. If you’re trying to build up your soil, amend it, revitalize it, and do all of the things for soil health, then you’ll want to be aware of what can wash your soil literally down the drain. In this article, we will explore the different types of soil erosion, their causes, impacts, and effective erosion control measures to preserve natural resources for future generations.
This post is all about different types of soil erosion.
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Different Types of Soil Erosion: What Are They and How to Prevent It
As gardeners, whether you grow flowers, vegetables, or both, keeping your soil in the garden is super important. Although soil erosion is natural process, it’s oftentimes sped up by our own activities. You may not even be aware that you’re contributing to it. As growers, we’re constantly amending our soil, adding soil, revitalizing it, and trying to make it healthier. However, none of that will matter if it’s just going to wash away. There are many different types of soil erosion to be aware of: water erosion, wind erosion, mass movement, tunnel erosion, human activities, overgrazing, and mass wasting. These are just some of the examples of soil erosion. There are different types of erosion within some of these categories, but I’ll review some of the most common.
Water Erosion: The Impact of Rainfall and Water Flow
Water has the ability to transform our landscape, even in ways we could never imagine. It has the ability to slowly eat away at rock, or water can swiftly sweep through and change an entire waterway. Water erosion is one of the most common types of soil erosion and occurs when rainfall intensity, surface runoff, and water flow remove the top layer of soil. This type of erosion can significantly affect soil structure, soil quality, and crop yields. Even within my neighborhood you can witness soil erosion happening. Lots of people in my neighborhood get their own landscaping done and the effects of that can be seen after a good rain. Lots of soil slowly making its way off their property, eventually winding up in the road. The main types of water erosion include: splash erosion, sheet erosion, rill erosion, gully erosion, and bank erosion.
In order to prevent soil erosion, we must first understand what causes it.
Splash Erosion: The First Stage of Water Erosion
Splash erosion happens when raindrop impact dislodges fine particles of soil, reducing the protective layer of vegetation cover. This can lead to the formation of shallow surface disturbances, making the soil more vulnerable to further erosion.
The NSW Department of Primary Industries dives a little deeper into this topic,
The explosive impact breaks up soil aggregates so that individual soil particles are ‘splashed’ onto the soil
surface. The splashed particles can rise as high 60cm (almost 2 feet) above the ground and move up to 1.5 metres (almost 5 feet) from the point of impact. The particles block the spaces between soil aggregates, so that the soil forms a crust that reduces infiltration and increases runoff.Jenkins, A. (n.d.) Soil erosion solutions. NSW Department of Primary Industries. https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0003/255153/fact-sheet-1-types-of-erosion.pdf
That last part of the quote “the soil forms a crust that reduces infiltration and increases runoff” is where the problem lies. Have you ever noticed after it rains that the soil has developed a crust? It becomes hard and very compact which makes it hard for water to flow through the soil the way it should. This is why it’s so crucial that soil remains completely covered by some sort of material – straw, mulch, leaves, etc. By keeping it covered, it keep this soil nice and ‘fluffy’, making the soil easy to work with. You can also plant cover crops since it provides a way for the soil to stay in place.
Sheet Erosion: The Loss of Fertile Soil
Sheet erosion occurs when a thin layer of soil is removed evenly across a soil surface due to water flow. This often goes unnoticed but leads to loss of topsoil, reducing soil fertility and harming agricultural lands. To put this in perspective, half of the topsoil throughout the world has been lost. It’s not as simple as just adding topsoil back on top.
“Less than a tenth of a millimeter of soil forms per year in some places, though the amount can vary depending on the environment. Compare that to the rate of topsoil erosion in agricultural regions of the United States: around half a millimeter per year, or 5 times as much.”
Scharping, N. (2024, June 11). Agricultural Lands Are Losing Topsoil—Here’s How Bad It Could Get. EOS. https://eos.org/articles/agricultural-lands-are-losing-topsoil-heres-how-bad-it-could-get
If you think of how much land used for agriculture in the United States, that’s a lot of area to cover with new topsoil. Agricultural practices such as regenerative farming help to reduce the loss of topsoil through reduced or no tillage, planting cover crops, crop rotation, integrating livestock with farming, and other techniques.
Rill Erosion: The Formation of Small Channels
Rill erosion develops when surface runoff cuts small, shallow channels into loose soil. These channels can be up to a foot deep! You might see this for example during deforestation. Deforestation not only removes the trees, but it also removes other vegetation and ground cover. As another example, this can also occur during periods of forest fires. If left untreated, these rills can deepen and contribute to gully erosion.
Gully Erosion: Significant Damage to Agricultural Lands
Gully erosion is an advanced form of rill erosion where large amounts of soil are washed away, forming deep gullies. Typically, these form when soil is washed away along drainage lines. This can lead to land degradation and make areas unsuitable for crop production. It’s critical to maintain vegetation on the land, particularly along drainage lines.
Bank Erosion: The Erosion of River Banks
Bank erosion occurs along river banks, where water flow gradually removes soil, affecting nearby bodies of water. This process can be accelerated by heavy rainfall, lack of vegetation cover, and human activities such as construction sites, road construction, and deforestation near or along river banks. Vegetation’s roots helps to stabilize the bank. By removing the vegetation, this causes destabilization. This type of erosion causes sedimentation – soil begins to accumulate in the riverbed affecting the flow of the water. It also affects the water quality and thereby affects fish, wildlife, and destroys their habitats.
Wind Erosion: The Effect of Strong Winds
Wind erosion is prevalent in arid areas with sandy soils and bare soil. When strong winds pick up loosened soil particles, they create dust storms, reducing air quality and causing soil degradation. Activities such as agricultural practices like tillage, mono crops, and overgrazing contribute to ruining the soil and vegetation in an area. This type of erosion can be controlled with cover crops, erosion control blankets, and conservation practices.
Mass Movement: The Role of Gravity in Soil Erosion
It’s a more extreme version of erosion. However, there are causes that have led the ground up to this point in many cases. Mass movement (also known as soil break or mass wasting), is a physical process where gravity causes soil and rock to move downhill. This occurs on steep slopes, especially after heavy rainfall or human activity such as vehicle traffic and land use changes, and results in incidents like rockfalls and landslides. Activities like vehicle traffic and land use changes can destabilize areas like hillsides.
Tunnel Erosion: The Hidden Type of Soil Erosion
Tunnel erosion occurs when water flow creates underground tunnels, weakening the soil structure. This can result in sudden collapses, leading to severe land degradation. Tunnel erosion eventually leads to gully erosion which was previously discussed. It results in structural damage to roadways and building, can cause injuries to animals, and destroys habitats for wildlife.
The Impact of Human Activities on Soil Erosion
Human activities such as deforestation, construction sites, road construction, and parking lot development contribute to various types of soil erosion. Poor land use practices, lack of organic matter, and removal of the protective layer of vegetation accelerate the process of erosion.
How does this apply to our own gardens, farms, homesteads, etc?
We are the stewards of our land – regardless of how much of it we have. Since many who may be reading this post are gardening and growing their own food, it’s imperative that we do so in a more regenerative way than what has been traditionally done.
Erosion Control Measures: Protecting Soil for Future Generations
To prevent significant damage from different types of erosion, implementing sustainable land management practices is essential. Some effective erosion control measures include:
- Crop rotation to improve soil fertility and soil quality
- Using silt fences and hybrid-turf instant armor mats at construction sites
- Planting cover crops to protect fertile soil
- Installing erosion control blankets on steep slopes
- Avoiding overgrazing and excessive vehicle traffic on loose soil
- Managing water flow to prevent wave action along river banks
Conclusion
Soil erosion is a major problem caused by both natural forces and human activity. Understanding the different types of soil erosion, their causes, and implementing conservation practices can help maintain agricultural productivity, protect natural resources, and ensure a healthier planet for future generations. By using the right product and adopting sustainable practices, we can mitigate the effects of soil degradation and preserve the Earth’s surface for years to come.
This post was all about different types of soil erosion.
