The Causes and Indicators of Wind Erosion

By PSU EcoMerge Capstone - 10:53 AM

What causes wind erosion?
Wind erosion can occur only when windspeed at the soil surface is sufficient to lift and transport soil particles. Moist soils and soils with stable aggregates or rock fragments are less likely to be eroded than other soils. Thick lichen crusts provide greater resistance to erosion than thin crusts. Sand moving across the soil surface wears away soil aggregates and thin crusts, causing more soil particles to become detached and to be blown away. A cover of plants disrupts the force of the wind.

Soils are more susceptible to wind erosion where disturbance exposes individual particles and soil aggregates to the wind. When physical or biological crusts are crushed or broken apart by such disturbances as heavy grazing, vehicle or foot traffic, and water erosion, particle movement begins at the lower windspeeds. The following conditions increase the susceptibility of the soil to wind erosion:

• crushed or broken soil surface crusts during windy periods;
• a reduction in the plant cover, biological crusts, and litter, resulting in bare soil;
• a decrease in the amount of organic matter in the soil, causing decreased aggregate stability; and
• long, unsheltered, smooth soil surfaces.

What are some indicators of wind erosion?

Erosion and the risk of erosion are difficult to measure directly. Other soil properties that affect erosion and can change with management, including soil surface stability, aggregate stability, and content of organic matter, can be measured. Measuring these properties can shed light on the susceptibility of a site to erosion. Comparing visual observations along with quantitative measurements to the conditions in the ecological site description or a reference area helps to provide information about soil surface stability and wind erosion.

The visual indicators used to identify past erosion include:

• bare soil,
• wind-scoured areas between plants,
• a drifted or rippled soil surface,
• loose sand on physical crusts,
• biological crusts buried by soil,
• pedestaled plants or rocks,
• exposed roots,
• soil deposition on the leeward side of plants and obstacles,
• litter movement to the leeward side of plants and obstacles,
• exposure of subsoil at the surface,
• reduced plant growth, and
• dust clouds.

When measured over time, the following indicators can be used to predict where accelerated erosion is likely to occur in the future:

• an increase in the amount of bare ground or in the size of bare patches,
• reduced soil surface stability, and
• a reduction in the amount of organic matter.

Please spend a moment taking a look at this webpage that shows hi def picture examples of recent dust storms in the US. It shows the mayhem that dust storms cause. Please be aware of wind erosion and how it affects the earths soil. Try and learn from our past so we don't have to repeat it. Thank You.


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