Introduction

The wind is an essential geomorphic agent that leads to landforms on Earth. This type of erosion is also called Aeolian erosion(Also spelled Eolian). It refers to wind activity in the study of geology and weather. It refers to the wind’s ability to shape the surface of the Earth. Winds erode and are effective agents in regions with sparse vegetation cover, a lack of soil moisture, and an ample supply of unconsolidated sediments. In this article, we will study in detail the science behind the formation of Wind Landforms: Erosional.

Process

• Deflation – is the removal, lifting, and carrying away of dry dust particles by wind. Deflation causes depression such as Blowouts
• Abrasion – refers to the process where wind loaded with sand grains erodes the rock by grinding against its walls. This process is also called Sandblasting
• Attrition – refers to the wear and tear of sand particles when they are transported

Erosional features of wind:

• Pediplains – Pediplains are the high relief structures in deserts formed by being reduced to low featureless plains by wind erosion
• Deflation Hollows – Also called Blowouts, are caves or hollows formed by the removal of particles by wind. These are generally small but may stretch up to several kilometres in diameter
• Mushroom Rocks – Also called a Rock pedestal, these are naturally occurring rocks that resemble a mushroom. They are mainly caused by Wind erosion and weathering
• Inselbergs – Also called monad nock, it is an isolated hill, outcrop, knob, ridge, or a small mountain that abruptly rises from a gentle slope
• Demoiselles – Demoiselles are pillars of rocks that stand above softer rocks due to differentiated erosion of both hard and soft rocks
• Zeugen – is a table-shaped area of rocks found in both arid and semi-arid regions. It is formed when a relatively more resistant rock erodes slower than the soft rocks around it
• Yardangs – Yardangs are a ridge of rock formed by wind, parallel to the prevailing wind direction
• Wind bridges and windows – Powerful wind continuously abrades stone lattices, thus creating holes. These holes are sometimes widened to an extent to reach each other at the end, thus creating an effect like that of a window, creating Wind Windows. On the other hand, Wind Bridges form when the holes are wide enough to make an arch-like structure

Effects of Wind erosion

• The first effect of wind erosion is the winnowing of light particles. Wind erosion being selective carries only the finest particles such as organic matter, clay, and loam for many kilometres
• Another spectacular form is dunes. Dunes are mounds of more or less sterile sand particles, which move as the wind takes them, burying oases and cities
• Another effect is the degradation of sedimentation crusts on the surface of stripped soils or the weathering of rocks at their base
• Sheets of sand travelling close to the ground can damage crops such as millets or cotton seedlings in semi-arid zones
• Wind erosion reduces the soil’s capacity to hold nutrients and water, thus making the soil and environment drier

Factors affecting wind erosion

• The aridity of climate – Although the aridity of a place determines wind erosion, areas that receive high rainfall can also face wind erosion when certain months of the year are dry, and the soil is tilled in a way that crushes the surface
• Wind speed – Wind erosion is determined by the wind speed, particularly if the speed exceeds about twenty km/in or six m/s over dry soils. Wind phenomena increase with strong, regular prevailing winds and gusts
• Soil texture – Loamy sand rich in particles (between 10 and 100 microns in size) is most vulnerable to Aeolian erosion. Clayey soil, rocky soil, coarse and gravelly soil are more resistant to wind erosion because they are heavier. 80 microns is the optimum size for wind erosion
• Soil structure – Soils with less structure improving matter such as organic matter, iron, and free aluminium and lime are more prone to wind erosion. Sodium and salt also foster the wind erosion of soil as they are responsible for forming a layer of dust on the surface
• Soil surface – Condition of the soil surface plays one of the most crucial factors behind the intensity of a soil getting weathered by wind erosion. If the surface is stony, then erosion is less. If the surface is smooth and loose, then the erosion is maximum
• Vegetation – The presence of vegetation on the surface reduces the chances of erosion
• Soil moisture – Soil moisture increases the cohesion of sand and loam, thus preventing erosion temporarily

Wind erosion control

• Increasing soil cohesion is the primary way to reduce wind erosion. An increase in cohesion improves the soil’s capacity to provide resistance to wind
• Increasing the roughness of the soil-Roughness can be increased by using cropping techniques that leave large clods behind. The creation of controlled ridges also leads to the soil’s capacity to resist wind erosion. Leaving behind crop residues is also a cheap and proven way to reduce soil erosion by wind
• Increasing plant cover is the most sustainable way to reduce soil weathering by the wind. It increases soil cohesion, makes the soil fertile, and leads to a greener and moisture-laden environment
• Wind-Breaks: These are effective in two ways. They reduce wind speed at the ground level to reduce soil erosion and evaporation

Conclusion

From the above-mentioned facts, we can infer that wind not only makes us feel cool when it blows across our faces but also forms landforms and damages soil by eroding them. Wind landforms by Aeolian erosion take many years to form, and it is a continuing process. The wind, just like any other agent, affects the topography of the planet to such an extent that it creates new avenues to dissect, analyse and understand. These landforms also have an attractive aesthetic and indigenous value attached to them.