por The types of erosion they depend on the natural agent causing the process, being water and wind the most common elements. Like all natural processes that take place on the earth’s surfaces, the force of gravity plays a very important role.
There are other factors that erode the soil such as ice, temperature and the force exerted by the movement of the waves. Some human activities such as agriculture, deforestation and grazing can increase the impact of natural agents of erosion.
The complete concept of erosion also involves the process of wearing down and shaping the soil or the rocky crusts of the geographical landscape in their original position, up to the transport of all the materials removed by the action of the agents involved.
Most soil material removed in this way is soil or rock debris, which gradually breaks down into smaller bodies as it is transported.
Planet Earth offers a number of geographic settings or landforms such as mountain ranges and peaks, valleys and canyons, stony shorelines and cliffs, whose features have been formed over time by erosion.
The term erosion comes from the Latin erosion what is the action of the verb erodere and it means «gnaw», from which other words such as «rodent» and «corrosive» also originate.
Classification of types of erosion
– Erosion by water
Moving or flowing water is the most important erosive agent of all. Although it may not seem like it, water is one of the most powerful forces on planet earth. By action of water, there are three types of erosion:
River
The erosion of the banks of the rivers is caused by the action of friction or constant rubbing of the flow of water.
This flow carries soil sediments into the downstream body of water, which act as an erosion tool by wearing away each other or wearing away rocks and soil surfaces.
Progressively, this wear removes more and more sediment as the volume and speed of water flow increases.
In tributaries with harder or arid soils, both the constant flow of water and the growth and decrease of its channel, gradually carve out an ever deeper or wider channel on the surface. As an example of this phenomenon we have the Grand Canyon in Arizona, United States.
precipitation
The land surfaces not affected by the water of the rivers, is exposed to the continuous force of erosion due to the action of the rains. If the soil is protected by trees such as forest or jungle bodies, rainwater will affect the soil less aggressively.
The water will fall more gently, which will allow the earth on the ground to filter and absorb it naturally.
However, constant rains in sloping forested areas can cause landslides that could drag trees and rocks.
On bare ground, raindrops can impact the ground with enough force to break its structure, in what is called the effect of splash erosion.
The particles and sediments «splash» up to 60 centimeters high, which then fall and cover the natural pores of the earth through which it filters and absorbs water.
Thus, the water accumulates on the surface and as the flow increases and drains away due to gravity, it takes land with it.
This effect is called surface erosionwhich removes the first layers of soil necessary for the accumulation of organic matter.
Rain on unprotected soils can create other erosive effects such as ditches, channels And till tunnels.
Surf
The erosion of the coasts is a product, mainly, of the action of the waves of the sea. The impact of the water added to the abrasion of particles, sediments, sand and stones transported in the swaying of the waves, gradually wear down the shores.
This effect is more noticeable on rockier coasts where the force of the waves progressively eats away at the stone walls of the cliffs, revealing the bedrock. Thanks to this action, there are rock formations such as coastal arcs.
As an example of this phenomenon we have the arches of Playa de las Catedrales or Playa de las Aguas Santas in Ribadeo, Spain.
– Eolic erosion
It is the degradation and wear of dry and rocky lands also known as desertification. As its name indicates, its action is the wind, which is one of the least aggressive erosive elements and whose effects can take years.
It happens when strong winds blow over arid soils unprotected by vegetation or with very little vegetation. The wind carries sand and small rock particles in the air that wear away the rocky surfaces of the terrain.
This gradually causes the rocks to fracture and release more particles into the air, increasing the erosive factor in the wind. With the transfer from one side to another of the materials, soils and mountains are molded.
Also in sandier areas, the wind simply displaces bodies of sand such as dunes or dunes progressively, being able to completely change the landscape in a matter of days or hours. Sandstorms cause this effect very quickly.
As an example of this phenomenon we have the Sahara desert, both in the areas with dunes and the rockiest.
– Glacial erosion
It basically occurs when ice sheets move downhill on a mountainous slope. The weight of the sliding ice exerts a crushing effect on the ground, opening or digging its way by force.
The ice may also carry with it portions of ground rock as it moves, which probably became covered by ice and are part of the body of the glacier. In this way, the ice wears down the soil, creating valleys and shaping mountains.
– Erosion by temperature
It is the type of erosion that is produced by temperature changes caused by the exposure of land surfaces to sunlight. The rock, for example, when receiving high temperatures expands, which causes it to begin to break, creating fissures.
Eventually, the cracks compromise the structure that holds the rock together and separate enough for gravity or wind to move or displace them from their original site.
References
Abigail Jenkins. Soil Erosion Solutions – Fact sheet 1: Types of erosion (online document). Department of Primary Industry. NSW Government. Retrieved from dpi.nsw.gov.au. Andrew Alden (2017). What Is Erosion and How Does It Shape the Earth’s Surface? – Erosion Is a Central Concept in Geology. Thought Co. Retrieved from thoughtco.com. ca (2004). What are the Different Types of Erosion? Virtual Science Fair. Retrieved from odec.ca/projects. Queensland Government site (2013). Types of erosion. The State of Queensland. Retrieved from qld.gov.au. The Editors of Encyclopedia Britannica (2017). Encyclopedia Britannica Inc. Retrieved from britannica.com. Mandy Barrow. Types of Erosion. Rivers Homework Help – Homework Help. Retrieved from primaryhomeworkhelp.co.uk. Paul Gregg (2008). Soil erosion and conservation. Te Ara – The Encyclopedia of New Zealand. Retrieved from TeAra.govt.nz.