Types of erosion
Aug 04, · The four types of erosion are sheet erosion, rill erosion, gully erosion and splash erosion. Erosion is defined as the withering away of the surface of land by either rain or irrigation water, wind or ice. Sheet erosion occurs when a very thin layer of surface dirt or soil is removed from a . Start studying 4 Types of Erosion. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
In earth diffreenterosion is the action of surface processes such as water flow or wind that removes how to regrout ceramic tile floorrockor dissolved material from one location on the Earth's crustand then transports it to another location.
Erosion is distinct from weathering which involves no movement. Agents of erosion include rainfall ;  bedrock wear in rivers ; coastal erosion by the sea and waves ; glacial plucking, abrasionand scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes what are the 4 different types of erosion steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded.
Typically, physical erosion proceeds fastest on steeply sloping surfaces, and rates may also be sensitive to some climatically-controlled properties including amounts of water supplied e.
Feedbacks are also possible between rates of erosion and the amount of eroded material that is already carried by, for example, a river or glacier. While erosion is a natural process, human activities have increased by times the rate at which erosion is occurring globally.
On-site impacts include decreases in agricultural productivity and on natural landscapes ecological collapseboth what are the 4 different types of erosion of loss of the nutrient-rich upper soil layers. In some cases, this leads to desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses.
Intensive agriculturedeforestationroadsanthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. Rainfalland the surface runoff which may result from rainfall, produces four main types of soil erosion : splash erosionsheet erosionrill erosionand gully erosion.
Splash erosion is generally seen as the first and least severe stage in the soil erosion process, which is followed by sheet erosion, then rill erosion and finally gully erosion the most severe of the four. In splash erosionthe impact of a falling raindrop creates a small crater in the soil,  ejecting soil particles.
If the soil is saturatedor if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs. If the runoff has sufficient flow energyit will transport loosened soil particles sediment down the slope. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes.
Generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of the order of a typess centimetres about an inch or less and along-channel slopes may be quite steep.
This means that qhat exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow, removing soil to a considerable depth.
Extreme gully erosion can progress to formation of badlands. These form under conditions of high relief on easily eroded bedrock in climates favorable to erosion. Conditions or disturbances that limit the growth of protective vegetation rhexistasy are a key element of badland formation.
Valley or stream erosion occurs with continued water flow along a linear feature. The erosion is both downwarddeepening the valleyand headwardextending the valley into the hillside, creating head cuts and steep banks.
In the earliest stage of stream erosion, the erosive activity is dominantly vertical, the valleys have a typical V cross-section and the stream gradient is relatively steep.
When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain. The stream gradient becomes nearly flat, and lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far the most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load.
In such processes, it is not the water alone that erodes: suspended abrasive particles, pebblesand boulders can also act erosively as they traverse a surface, in a process known as traction.
Bank erosion is the wearing away whay the banks of a stream or river. This is distinguished from changes on the bed of the watercourse, which is referred to as scour. Erosion and changes in the form of river banks may be measured by inserting metal rods into the bank and marking the position of the bank surface along the rods at different times. Thermal erosion how to send flowers to china the result of melting and weakening permafrost due to moving water.
Rapid river channel migration observed in the Lena River of Siberia is due to thermal erosion, as these portions of the banks are composed of permafrost-cemented non-cohesive materials. Thermal erosion also affects the Arctic coastwhere wave action and near-shore temperatures combine to undercut permafrost bluffs along the shoreline and cause them to fail. Annual erosion rates along a kilometre mile segment of the Beaufort Sea shoreline averaged 5. Most river erosion happens nearer to the mouth of a river.
On a river bend, the longest least sharp side has slower moving water. Here deposits build up. On the narrowest tjpes side of the bend, there is faster moving water so this thee tends to erode away mostly.
Digferent erosion by a large river can remove enough sediments to produce a river anticline as isostatic rebound raises rock beds unburdened by erosion of overlying beds. Shoreline erosion, which occurs on both eerosion and sheltered coasts, primarily occurs through the action of currents and waves but sea level tidal change can also play a role.
Hydraulic action takes place when the air in a joint is suddenly compressed by a wave closing the entrance of the joint. This then cracks it. Wave pounding is when the sheer energy of the wave hitting the cliff or rock breaks pieces off.
Abrasion or corrasion is caused by waves launching sea load at the cliff. It is the most effective and rapid form of shoreline erosion not to be confused with corrosion. Corrosion is the dissolving of rock by carbonic acid in sea water. This then makes the material easier to wash away. The material ends up as shingle and sand. Another significant source of erosion, particularly on carbonate coastlines, is boring, scraping and grinding of organisms, a process termed bioerosion.
Sediment is transported along the coast in the direction of the prevailing current longshore drift. When the upcurrent supply of sediment is less than the amount being carried away, erosion occurs. When the upcurrent amount of sediment is greater, sand or gravel banks will tend to form as a result of deposition.
These banks may slowly migrate along the coast in the direction of the longshore drift, alternately protecting and exposing parts of the coastline. Where there is a bend in the coastline, quite often a buildup of eroded material occurs forming a long narrow bank a spit.
Armoured beaches and submerged offshore sandbanks may also protect parts of a coastline from erosion. Over the years, as the shoals gradually shift, the erosion may be redirected to attack different parts of the shore. Erosion of a coastal surface, followed by a fall in sea level, can produce a teh landform called a raised beach.
Chemical erosion is the loss of matter in a landscape in the form of solutes. Chemical erosion is usually calculated from the solutes found in streams. Formation of sinkholes and other features of karst topography is an example of extreme chemical erosion. In an abrasion process, debris in the basal ice scrapes along the bed, polishing typs gouging the underlying rocks, similar to sandpaper on wood.
Scientists have shown that, in addition to the role of temperature played in valley-deepening, other glaciological processes, such as erosion also control cross-valley variations.
In a homogeneous bedrock erosion pattern, curved channel cross-section beneath the ice is created. Though the glacier continues to incise vertically, the shape of the channel beneath the ice eventually remain constant, reaching a U-shaped parabolic steady-state shape as we now see in glaciated valleys. Scientists also provide a numerical estimate of the time required for the ultimate formation of a steady-shaped U-shaped valley —approximatelyyears.
In a weak bedrock containing material more erodible than the surrounding rocks erosion pattern, on the contrary, the amount of over deepening is limited because ice velocities and erosion rates are reduced. Glaciers can also cause pieces of bedrock to crack off in the process of plucking.
Whwt ice thrusting, the glacier freezes to eroion bed, then as it surges forward, it moves large sheets of how to install bike forks sediment at the base along with the glacier.
This method produced some of the many thousands of lake basins that dot the edge of the Canadian Shield. Differences in the height of mountain ranges are not only being the result tectonic forces, such as rock uplift, but also local climate variations.
Scientists use global analysis of topography to show that glacial erosion controls the maximum height of mountains, as the relief between mountain peaks and the snow line are generally confined to altitudes less than m. Ongoing research is showing that while glaciers tend to decrease mountain size, in some areas, glaciers can actually reduce the rate of erosion, acting as a glacial armor.
Depending on glacier regime, even steep alpine lands can be preserved through time with the help of ice. Scientists have proved this theory by sampling eight summits of northwestern Svalbard aee Be10 and Al26, showing that northwestern Svalbard transformed from a glacier-erosion state under relatively mild glacial maxima temperature, to a glacier-armor state occupied by cold-based, protective ice during much colder glacial maxima temperatures as the Quaternary ice age progressed.
These processes, combined with erosion and transport by the water network beneath the glacier, age behind glacial landforms such as morainesdrumlinsground moraine tillkames, kame deltas, moulins, and glacial erratics in their wake, typically at the terminus or during glacier retreat. The best-developed glacial valley morphology appears to be restricted to landscapes with low rock uplift rates less than or equal to 2 mm per year and high what does ocean acidification cause, leading to long-turnover times.
Where rock uplift rates exceed 2 mm per year, glacial valley morphology has generally been significantly modified in postglacial time. Interplay of glacial erosion and tectonic forcing governs the morphologic impact of glaciations on active orogens, by both influencing their height, and by altering the patterns of erosion during subsequent glacial periods via a link between rock uplift and valley cross-sectional shape. At extremely high flows, kolksor vortices are formed by large volumes of rapidly rushing fo.
Kolks cause extreme local erosion, plucking bedrock and creating pothole-type geographical features called rock-cut basins. Examples can be seen in the flood regions result eroion glacial Lake Missoulawhich created the channeled scablands in the Columbia Basin region of eastern Washington.
Wind erosion is a major geomorphological force, especially in arid and semi-arid regions. It is also a major source of land degradation, evaporation, desertification, harmful airborne dust, and crop damage—especially after being increased far how to get a ton of money in skyrim natural rates by human activities such as deforestationurbanizationand agriculture.
Wind erosion is of two primary varieties: deflationwhere the wind whwt up and carries away loose particles; and abrasionwhere surfaces are worn down as typez are struck by airborne particles carried by wind.
Deflation is divided into three categories: 1 surface creepwhere larger, heavier particles slide or roll along the ground; 2 saltationwhere particles are lifted a short height into the air, and bounce and saltate across the surface of the soil; and 3 suspensionwhere very small and light particles are lifted into the air by the wind, and are often carried for long distances. Wind erosion is tue more severe in arid areas and during times of drought.
For example, in the Differebt Plainstge is estimated that soil loss how to regrout ceramic tile floor to wind erosion can be as much as times greater in drought years than in wet years.
Mass movement is the downward and outward movement of rock and sediments on a sloped surface, mainly due to the force of gravity. Mass movement is an important part of the erosional process and is often the first stage in the breakdown and transport of weathered materials in mountainous areas. Mass-movement processes are always occurring continuously on all slopes; some mass-movement processes act very slowly; others occur very suddenly, often with disastrous results.
Any perceptible down-slope movement of rock or sediment is often referred to in general terms as a landslide. However, landslides can be classified in a much more detailed way that reflects the mechanisms responsible for the movement and the velocity at which the movement occurs.
One of the visible topographical manifestations of a very slow form of such activity is a scree slope. Slumping happens on what is the climate in the coastal region hillsides, occurring along distinct fracture zones, often within materials like clay that, once released, may move quite rapidly downhill.
They will often show a spoon-shaped isostatic depressionin which the material has begun rypes slide downhill.
The different soil erosion types are explained below. Rain Drop or Splash Erosion The erosion due to the impact of falling raindrops on soil surface leading to the destruction of the crumb structure is known as the raindrop or splash erosion. There are many different forces in nature that cause erosion. Depending on the type of force, erosion can happen quickly or take thousands of years. The three main forces that cause erosion are water, wind, and ice.
Learn more. Soil erosion is a widespread problem in rural and urban Queensland. If we want to save our soils, we need to understand the different types of erosion that can occur. Raindrops hit bare soil with enough force to break the soil aggregates. These fragments wash into soil pores and prevent water from infiltrating the soil.
Water then accumulates on the surface and increases runoff which takes soil with it. Well-structured soils are less prone to break up, and the impact of raindrops is minimised if the soil surface is protected by plant or litter cover. The vulnerability of soils to water erosion depends on:. Hill slopes are prone to sheet erosion and rill erosion. The amount of hill slope erosion largely depends on how the land is used. Sheet erosion occurs when a thin layer of topsoil is removed over a whole hillside paddock—and may not be readily noticed.
Rill erosion occurs when runoff water forms small channels as it concentrates down a slope. These rills can be up to 0. If they become any deeper than 0. Scalding can occur when wind and water erosion removes the top soil and exposes saline or sodic soils. Raindrop impact alone can result in large amounts of soil being moved. However water or wind moving over the surface will remove more soil, and contribute to sheet, rill and gully erosion. Erosion also tends to remove the lighter, smaller soil particles first such as clay and silt , leaving fine and coarse sand behind.
A combination of large amounts of fine sand and small amounts of clay at the surface means the soil tends to seal and set hard, which limits infiltration water entering the soil. Gully erosion happens when runoff concentrates and flows strongly enough to detach and move soil particles.
For example, a waterfall may form, with runoff picking up energy as it plunges over the gully head. Splashback at the base of the gully head erodes the subsoil and the gully eats its way up the slope.
Gullies may develop in watercourses or other places where runoff concentrates. In cultivation or pastures, advanced rill erosion can develop into gully erosion. This type of erosion is highly visible and affects soil productivity, restricts land use, and can damage roads, fences and buildings. Gully depth is often limited by the depth of the underlying rock which means gullies are normally less than 2m deep.
However, gullies may reach depths of 10—15m on deep alluvial and colluvial soils. Tunnel erosion is the removal of subsoil. When water penetrates through a soil crack or a hole where a root has decayed, the soil disperses and is carried away with the flow to leave a small tunnel.
Initially, the surface soil remains relatively intact but, with every flow, the tunnel becomes larger and the soil may eventually collapse and form a gully. The whole process speeds up significantly if an outlet is provided such as an existing gully or cutting in a roadside as this allows free flow of subsurface drainage water.
Soils vulnerable to tunnel erosion have dispersible subsoils with naturally high levels of sodium. Such soils are referred to as being sodic and are called Sodosols. When clods of these soils are exposed to water, they readily break down into individual particles of sand, silt and clay which are easily removed as water moves through the subsoil. The major cause of stream bank erosion is the destruction of vegetation on river banks generally by clearing, overgrazing, cultivation, vehicle traffic up and down banks or fire and the removal of sand and gravel from the stream bed.
These areas are subjected to high velocity floods that erode soils with insufficient surface cover. This erosive flooding can remove the entire layer of cultivated topsoil exposing compacted subsoils.
It is common for such areas to be stripped of 0. Problems can also occur at the end of a flood event when slow moving water flows over saturated soils. Mass movement occurs on cleared slopes in coastal areas. Gravity moves earth, rock and soil material downslope both slowly millimetres per year and suddenly e. During periods of prolonged and heavy rainfall, water entering permeable soils can be stopped by a barrier such as bedrock or a clay-rich soil horizon.
The heavy weight of this saturated soil can slide downslope if it is sitting on a rock surface loosened by the build-up of water in the soil. It is better to prevent landslides than pay for expensive, time-consuming rehabilitation which may only be partially effective.
As excessive water intake is the most common trigger of landslip, avoid obstructions such as dams or cross-slope drains. It is most likely to occur when strong winds blow over light-textured soils that have been heavily grazed during drought periods.
These areas, which vary from a few square metres to hundreds of hectares, are difficult to revegetate due to:. Generally, wind erosion is not a serious issue in cropping areas. Most soils cultivated in Queensland have a heavy texture—forming relatively large aggregates that are too coarse to be carried by strong winds.
However, sandy soils are vulnerable to wind erosion because they cannot store very much moisture and have low fertility. This limits their use in Queensland, with only small areas where irrigation is available being cultivated for horticulture or growing vegetables. Home Environment, land and water Land, housing and property Land and vegetation management Soil management Erosion Types of erosion.
Print Types of erosion Soil erosion is a widespread problem in rural and urban Queensland. The vulnerability of soils to water erosion depends on: rainfall intensity erosivity —high intensity rainfall creates serious risk as heavy drops on bare soil causes the soil surface to seal nature of the soil erodibility —clay soils vary in their ability to withstand raindrop impact slope length—if a slope is long, water running down the slope becomes deeper and moves faster, taking more soil with it slope steepness—the speed of runoff increases on steep slopes, which increases the power of water to break off and carry soil particles.
Example of mass movement—landslip on a steep slope near Coolangatta, Queensland. Last updated: 18 December Last reviewed: 24 March Share this page: Facebook Twitter LinkedIn.