Soil erosion can affect agricultural land, rural areas, and urban environments. To save our soils from erosion, it helps to know the distinct types that occur.
This type of erosion happens when water and wind erosion swipes away the top layer of soil, exposing the sodic or saline soil below.
Wind and heavy rain remove lighter and smaller soil particles like clay and silt. This leaves fine and coarse sand behind, which can become hard set, hindering water infiltration.
A heavy downpour can lead to a significant amount of erosion by water. This type of erosion occurs when raindrops collide with bare soil. The force of the drop causes the soil to break up into what are known as aggregates, which are fragments that wash into soil spores and prevent water from infiltrating. When that happens, water can gather on the surface, increasing your chances and levels of runoff, which then takes the discarded soil with it.
When runoff becomes strong enough to detach and move soil particles, that phenomenon is known as gully erosion. You may find this type of erosion in places where runoff concentrates. Advanced rill erosion and sheet erosion develop into this type of erosive activity.
Gully erosion is visible and detrimental to soil productivity. It can damage fences, roads, and even buildings while restricting the use of valuable land.
Gullies that form due to this type of erosion can reach depths of up to fifteen meters with colluvial or alluvial soils. In most cases, the gullies are limited by the depth of underlying bedrock.
Stream Bank Erosion
Erosion along a stream bank is typically caused by a loss of bankside vegetation. This erosion is also caused by rainfall, wave action generated by boats or wind, and poor drainage within the bank profile. Cultivation or vehicle traffic and the removal of sand or gravel from the stream bed can also contribute to bank erosion.
Tunnel erosion occurs when water penetrates through a soil crack or hole caused by a decayed root. The effect is the removal of enough subsoil to form a small tunnel.
You can identify this type of erosion by surface soil that stays intact but with a tunnel that grows larger with every flow. Eventually, the tunnel can collapse, forming a gully.
Soil that is susceptible to this type of erosion often has naturally elevated levels of sodium, which means the soil is sodic of the family sodosols. When clods of these soils become exposed to water, they can break down into tiny sand particles, clay, and silt which are easily removed as water sifts through the subsoil.
Floodplains can make for effective agricultural lands because of the highly fertile soils and water availability for irrigation. Unfortunately, these areas are also subjected to floods that can dramatically erode the soil.
The risk of erosion on floodplains will depend on the velocity of the flooding and orientation of crop rows on arable land. The amount of protective cover offered by crops when flooding occurs also matters.
Wind erosion happens in arid areas when intense winds blow the top layer of light-textured soils away. Where you have bare areas on impermeable soils, you can get a problem called scalding. Even without scalding, wind erosion can make revegetation difficult. Wind erosion hits areas with sandy soils particularly hard because of a lack of moisture and low soil fertility.
Mass Movement Erosion
Mass movement occurs when rock and soil flow downslope. The erosion can be rapid in some cases or slow, where the soil and rock particles fall downhill at mere millimeters per year.
Different forms of mass movement can occur, including slumping, earthflow, soil creep, rock avalanches, and landslides.
The problem can be exacerbated by heavy rainfall, which causes saturated soil to slide downslope or water buildup causes the surface to loosen and fall.
The problem can also be caused by trees recently cleared from susceptible areas.
Why is it Important to Prevent Soil Erosion?
Soil has several important jobs. According to the UN's Food and Drug Agricultural Organization (FAO), soil helps to fight climate change by collecting carbon and reducing greenhouse gas emissions. Soil allows for water infiltration, which filters and keeps pollutants from invading the groundwater. Soil is also used to grow food for our growing population.
Soil erosion strips the soil of nutrients and degrades the soil, so it can’t do its many jobs properly.
Potential Solutions for Soil Erosion
Flexamat erosion control technology combines vegetation with permanent erosion control. Flexamat is effective at preventing the further eroding of your topsoil.
Flexamat permanent erosion control mats can prevent and stop soil erosion. Learn more by calling (513)772-6689.