Erosion is the carrying away or displacement of solids (sediment, soil, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down-slope movement in response to gravity or by living organisms (in the case of bioerosion). Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Gravitation is a natural Phenomenon by which objects with Mass attract one another Bioerosion describes the Erosion of hard ocean substrates by living organisms by a number of mechanisms

Erosion is distinguished from weathering, which is the process of chemical or physical breakdown of the minerals in the rocks, although the two processes may be concurrent. Weathering is the decomposition of earth rocks, Soils and their Minerals through direct contact with the planet's Atmosphere.

Erosion is an intrinsic natural process but in many places it is increased by human land use. Land use' is also often used to refer to the distinct land use types in Zoning. Poor land use practices include deforestation, overgrazing, unmanaged construction activity and road or building. Deforestation is the conversion of Forested areas to non-forest land for use such as Arable land, Pasture, urban use logged area or wasteland Overgrazing occurs when plants are exposed to Livestock Grazing for extended periods of time or without sufficient recovery periods Land that is used for the production of agricultural crops generally experiences a significant greater rate of erosion than that of land under natural vegetation. This is particularly true if tillage is used, which reduces vegetation cover on the surface of the soil and disturbs both soil structure and plant roots that would otherwise hold the soil in place. However, improved land use practices can limit erosion, using techniques such as terrace-building, conservation tillage practices, and tree planting. In Agriculture, a terrace is a leveled section of a Hilly cultivated area designed as a method of Soil conservation to slow or prevent the rapid

A certain amount of erosion is natural and, in fact, healthy for the ecosystem. An ecosystem is a natural unit consisting of all plants animals and micro-organisms( Biotic factors in an area functioning together with all of the non-living physical ( For example, gravels continuously move downstream in watercourses. Gravel is rock that is of a specific Particle size range In Geology, gravel is any loose rock that is larger than two millimeters (2mm Excessive erosion, however, does cause problems, such as receiving water sedimentation, ecosystem damage and outright loss of soil. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of

Contents 1 Causes 2 Effects 3 Erosion processes 3.1 Gravity erosion 3.2 Water erosion 3.2.1 Shoreline erosion 3.3 Ice erosion 3.4 Wind erosion 4 Soil Erosion and Climate Change 5 Tectonic effects of erosion 6 Materials science 7 Figurative use 8 Origin of term 9 See also 10 References 11 Further reading 12 External links

Causes

The rate of erosion tenses on many factors, including the amount and intensity of precipitation, the texture of the soil, the gradient of the slope, ground cover from vegetation, rocks, land use, how much water there is, and possibility of erosion from speed of a stream. Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to Soil texture is a Soil property used to describe the relative proportion of different grain sizes of Mineral particles in a soil Vegetation is a general term for the plant life of a region it refers to the Ground cover provided by plants The first factor, rain, is the agent for erosion, but the degree of erosion is governed by other factors.

The first three factors can remain fairly constant over time. In general, given the same kind of vegetative cover, you expect areas with high-intensity precipitation, sandy or silty soils and steep slopes to be the most erosive. Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles Silt is Soil or rock derived Granular material of a Grain size between sand and clay Soils with a greater proportion of clay that receive less intense precipitation and are on gentle slopes tend to erode less. Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and But here, the impact of atmospheric sodium on erodibility of clay should be considered (Schmittner and Giresse, 1999).

The factor that is most subject to change is the amount and type of ground cover. In an undisturbed forest, the mineral soil is protected by a litter layer and an organic layer. These two layers protect the soil by absorbing the impact of rain drops. These layers and the underlaying soil in a forest is porous and highly permeable to rainfall. Typically only the most severe rainfall and large hailstorm events will lead to overland flow in a forest. If the trees are removed by fire or logging, infiltration rates remain high and erosion low to the degree the forest floor remains intact. Severe fires can lead to significantly increased erosion if followed by heavy rainfall. In the case of construction or road building when the litter layer is removed or compacted the susceptibility of the soil to erosion is greatly increased.

Roads are especially likely to cause increased rates of erosion because, in addition to removing ground cover, they can significantly change drainage patterns especially if an embankment has been made to support the road. A road that has a lot of rock and one that is "hydrologically invisible" (that gets the water off the road as quickly as possible, mimicking natural drainage patterns) has the best chance of not causing increased erosion.

Many human activities remove vegetation from an area, making the soil easily eroded. Logging can cause increased erosion rates due to soil compaction, exposure of mineral soil, for example roads and landings. Logging is the process in which Trees are cut down for Forest management and Timber. However it is the removal of or compromise to the forest floor not the removal of the canopy that can lead to erosion. This is because rain drops striking tree leaves coalesce with other rain drops creating larger drops. When these larger drops fall (called throughfall) they again may reach terminal velocity and strike the ground with more energy then had they fallen in the open. In Hydrology, throughfall is the process which describes how wet leaves shed excess Water onto the ground surface A free falling object achieves its terminal velocity when the downward force of gravity ( Fg)equals the upward force of drag ( Fd) Terminal velocity of rain drops is reached in about 8 meters. Because forest canopies are usually higher than this, leaf drop can regain terminal velocity. However, the intact forest floor, with its layers of leaf litter and organic matter, absorbs the impact of the rainfall. (Stuart and Edwards)

Heavy grazing can reduce vegetation enough to increase erosion. Grazing generally describes a type of Predation in which an Herbivore feeds on Plants (such as Grasses, or more broadly on a multicellular Changes in the kind of vegetation in an area can also affect erosion rates. Different kinds of vegetation lead to different infiltration rates of rain into the soil. Forested areas have higher infiltration rates, so precipitation will result in less surface runoff, which erodes. Instead much of the water will go in subsurface flows, which are generally less erosive. Leaf litter and low shrubs are an important part of the high infiltration rates of forested systems, the removal of which can increase erosion rates. Leaf litter also shelters the soil from the impact of falling raindrops, which is a significant agent of erosion. Vegetation can also change the speed of surface runoff flows, so grasses and shrubs can also be instrumental in this aspect.

One of the main causes of erosive soil loss in the year 2006 is the result of slash and burn treatment of tropical forest. Slash and burn consists of cutting and burning of Forests or Woodlands to create fields for Agriculture or Pasture for Livestock, or The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 A forest is an area with a high density of Trees There are many definitions of a forest based on various criteria When the total ground surface is stripped of vegetation and then seared of all living organisms, the upper soils are vulnerable to both wind and water erosion. In a number of regions of the earth, entire sectors of a country have been rendered unproductive. For example, on the Madagascar high central plateau, comprising approximately ten percent of that country's land area, virtually the entire landscape is sterile of vegetation, with gully erosive furrows typically in excess of 50 meters deep and one kilometer wide. Madagascar, or Republic of Madagascar (older name Malagasy Republic) is an Island nation in the Indian Ocean off the southeastern In Geology and Earth science, a plateau, also called a high plateau or tableland, is an area of highland, usually consisting Vegetation is a general term for the plant life of a region it refers to the Ground cover provided by plants Shifting cultivation is a farming system which sometimes incorporates the slash and burn method in some regions of the world. For methods see Slash and burn Shifting cultivation is an Agricultural system in which plots of land are cultivated temporarily then abandoned Slash and burn consists of cutting and burning of Forests or Woodlands to create fields for Agriculture or Pasture for Livestock, or

Effects

Approximately 40% of the world's agricultural land is seriously degraded. ^[1] According to the UN, an area of fertile soil the size of Ukraine is lost every year because of drought, deforestation and climate change. The United Nations ( UN) is an International organization whose stated aims are to facilitate cooperation in International law, International security A drought is an extended period of months or years when a region notes a deficiency in its water supply Deforestation is the conversion of Forested areas to non-forest land for use such as Arable land, Pasture, urban use logged area or wasteland Climate change is any long-term significant change in the “average weather” that a given region experiences ^[2] In Africa, if current trends of soil degradation continue, the continent might be able to feed just 25% of its population by 2025, according to UNU's Ghana-based Institute for Natural Resources in Africa. The (UNU is an agency of the United Nations established in Tokyo in 1973 to "research into the pressing global problems of human survival development ^[3]

When land is overused by animal activities (including humans), there can be mechanical erosion and also removal of vegetation leading to erosion. An all-terrain vehicle (ATV is defined by the American National Standards Institute (ANSI as a vehicle that travels on low pressure tires with a seat that is straddled by In the case of the animal kingdom, this effect would become material primarily with very large animal herds stampeding such as the Blue Wildebeest on the Serengeti plain. A herd is a large group of animals The term is usually applied to mammals particularly Ungulates. The Blue Wildebeest ( Connochaetes taurinus) is a large Ungulate mammal of the Bovid family and one of two species of Wildebeest. This article is about a geographical region for the National Park see Serengeti National Park The Serengeti ecosystem is located in north-western Tanzania Even in this case there are broader material benefits to the ecosystem, such as continuing the survival of grasslands, that are indigenous to this region. This effect may be viewed as anomalous or a problem only when there is a significant imbalance or overpopulation of one species. Overpopulation refers to a condition where an Organism 's numbers exceed the Carrying capacity of its Habitat.

In the case of human use, the effects are also generally linked to overpopulation. Overpopulation refers to a condition where an Organism 's numbers exceed the Carrying capacity of its Habitat. For when large numbers of hikers use trails or extensive off road vehicle use occurs, erosive effects often follow, arising from vegetation removal and furrowing of foot traffic and off road vehicle tires. These effects can also accumulate from a variety of outdoor human activities, again simply arising from too many people using a finite land resource.

One of the most serious and long-running water erosion problems worldwide is in the People's Republic of China, on the middle reaches of the Yellow River and the upper reaches of the Yangtze River. Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES The Yellow River or Huang He / Hwang Ho ( Hatan Gol Queen river) is the second-longest river in China (after the Yangtze River) and the From the Yellow River, over 1. The Yellow River or Huang He / Hwang Ho ( Hatan Gol Queen river) is the second-longest river in China (after the Yangtze River) and the 6 billion tons of sediment flows into the ocean each year. The sediment originates primarily from water erosion in the Loess Plateau region of the northwest. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of The Loess Plateau ( also known as the Huangtu Plateau is a Plateau that covers an area of some 640000 km² in the upper and middle of China 's

Erosion processes

Gravity erosion

Mass Movement is the down slope movement of rock and sediments, mainly due to the force of gravity. Mass wasting, also known as slope movement, is the geomorphic process by which Soil, Regolith, and rock move downslope under Gravitation is a natural Phenomenon by which objects with Mass attract one another Mass Movement is an important part of the erosional process, as it moves material from higher elevations to lower elevations where other eroding agents such as streams and glaciers can then pick up the material and move it to even lower elevations. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. 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. A landslide is a geological phenomenon which includes a wide range of ground movement such as rock falls deep failure of slopes and shallow debris flows which can occur 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. Scree, also called talus and detritic cone, is a term given to broken rock that appears at the bottom of Crags mountain Cliffs or

Slumping happens on steep hillsides, occurring along distinct fracture zones, often within materials like clay that, once released, may move quite rapidly downhill. Slump is a form of Mass wasting event that occurs when loosely consolidated materials or rock layers move a short distance down a slope Clay is a naturally occurring material composed primarily of fine-grained Minerals which show plasticity through a variable range of Water content, and They will often show a spoon-shaped isostatic depression, in which the material has begun to slide downhill. Isostatic Depression is the term used by geologists for the sinking of large parts of the earth's crust into the Asthenosphere. In some cases, the slump is caused by water beneath the slope weakening it. In many cases it is simply the result of poor engineering along highways where it is a regular occurrence. * * * * * * * * * * * * * * * * * * * * * * Before adding any more images to this * * page please do carefully consider * * whether they would be mere decoration * * or actually improve

Surface creep is the slow movement of soil and rock debris by gravity which is usually not perceptible except through extended observation. However, the term can also describe the rolling of dislodged soil particles 0. 5 to 1. 0 mm in diameter by wind along the soil surface.

Water erosion

Splash erosion is the detachment and airborne movement of small soil particles caused by the impact of raindrops on soil.

Sheet erosion is the detachment of soil particles by raindrop impact and their removal downslope by water flowing overland as a sheet instead of in definite channels or rills. The impact of the raindrop breaks apart the soil aggregate. Particles of clay, silt and sand fill the soil pores and reduce infiltration. After the surface pores are filled with sand, silt or clay, overland surface flow of water begins due to the lowering of infiltration rates. Once the rate of falling rain is faster than infiltration, runoff takes place. There are two stages of sheet erosion. The first is rain splash, in which soil particles are knocked into the air by raindrop impact. In the second stage, the loose particles are moved downslope by broad sheets of rapidly flowing water filled with sediment known as sheetfloods. This stage of sheet erosion is generally produced by cloudbursts, sheetfloods commonly travel short distances and last only for a short time.

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. A rill is a narrow and shallow incision into soil resulting from Erosion by Overland flow that has been focused into a thin thread by soil surface Roughness Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically on the order of a few centimeters or less and slopes may be quite steep. These conditions constitute a very different hydraulic environment than typically found in channels of streams and rivers. Eroding rills evolve morphologically in time and space. The rill bed surface changes as soil erodes, which in turn alters the hydraulics of the flow. The hydraulics is the driving mechanism for the erosion process, and therefore dynamically changing hydraulic patterns cause continually changing erosional patterns in the rill. Thus, the process of rill evolution involves a feedback loop between flow detachment, hydraulics, and bed form. Flow velocity, depth, width, hydraulic roughness, local bed slope, friction slope, and detachment rate are time and space variable functions of the rill evolutionary process. Superimposed on these interactive processes, the sediment load, or amount of sediment in the flow, has a large influence on soil detachment rates in rills. As sediment load increases, the ability of the flowing water to detach more sediment decreases.

Where precipitation rates exceed soil infiltration rates, runoff occurs. Surface runoff turbulence can often cause more erosion than the initial raindrop impact.

Gully erosion results where water flows along a linear depression eroding a trench or gully. This article refers to the landform For other uses see Gully (disambiguation. This is particularly noticeable in the formation of hollow ways, where, prior to being tarmacked, an old rural road has over many years become significantly lower than the surrounding fields. A sunken lane, also called a hollow way or holloway, is a road which has over time fallen significantly lower than the land on either side

Valley or stream erosion occurs with continued water flow along a linear feature. The erosion is both downward, deepening the valley, and headward, extending the valley into the hillside. Headward erosion is a Fluvial process of Erosion that lengthens a Stream, a Valley or a Gully at its head and also 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 base level of a River or Stream is the lowest point to which it can flow often referred to as the 'mouth' of the river The stream gradient becomes nearly flat, and lateral deposition of sediments becomes important as the stream meanders across the valley floor. A meander in general is a bend in a sinuous watercourse also known as an oxbow loop or simply an Oxbow. 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, pebbles and boulders can also act erosively as they traverse a surface. A pebble is a clast of rock with a Particle size of 4 to 64 Millimeters based on the Krumbein phi scale of Sedimentology In Geology, a boulder is a rock with grain size of usually no less than 256 mm (10 Inches diameter

At extremely high flows, kolks, or vortices are formed by large volumes of rapidly rushing water. A kolk (also known as colc) is an underwater Vortex that is created when rapidly rushing water passes an underwater obstacle in boundary areas of high shear V erification of the O rigins of R otation in T ornadoes Ex periment or VORTEX, is a field project that seeks to understand how a Kolks cause extreme local erosion, plucking bedrock and creating pothole-type geographical features called Rock-cut basins. A rock-cut basin, in this usage of the term is a natural phenomenon Examples can be seen in the flood regions result from glacial Lake Missoula, which created the channeled scablands in the Columbia Basin region of eastern Washington. Glacial Lake Missoula was a prehistoric Proglacial lake in western Montana that existed periodically at the end of the last Ice age between 15000 and 13000 The Channeled Scablands are unique Geological Erosion features in the U The Columbia Basin, the Drainage basin of the Columbia River, occupies a large area–about 673396 square kilometres (260000 square miles—of the Pacific Washington ( is a state in the Pacific Northwest region of the United States. ^[4]

Shoreline erosion

See also: Beach evolution

Shoreline erosion, which occurs on both exposed and sheltered coasts, primarily occurs through the action of currents and waves but sea level (tidal) change can also play a role. A wave-cut platform, or shore platform is the narrow flat area often seen at the base of a Sea cliff or along a large lake shore caused by the action of the Southerndown is a village in Wales and suburb of Bridgend close to St Brides Major, Llantwit Major and Ogmore-by-Sea, mostly known for its beach (officially

Hydraulic action takes place when air in a joint is suddenly compressed by a wave closing the entrance of the joint. Hydraulic action is a form of Mechanical weathering caused by the force of moving water currents rushing into a crack in the rockface This then cracks it. Wave pounding is when the sheer energy of the wave hitting the cliff or rock breaks pieces off. Wave pounding is the ' Sledge hammer ' effect of tonnes of Water crashing against cliffs Abrasion or corrasion is caused by waves launching seaload at the cliff. Abrasion is mechanical scraping of a rock surface by Friction between rocks and moving particles during their transport in Wind, Glacier, Waves 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. Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings Carbonic acid (ancient name acid of air or aerial acid) has the formula H2CO3 Limestone cliffs are particularly vulnerable to this kind of erosion. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Attrition is where particles/seaload carried by the waves are worn down as they hit each other and the cliffs. This then makes the material easier to wash away. The material ends up as shingle and sand. A shingle beach is a Beach which is armoured with Pebbles or small to medium sized cobbles Another significant source of erosion, particularly on carbonate coastlines, is the boring, scraping and grinding of organisms, a process termed bioerosion. Bioerosion describes the Erosion of hard ocean substrates by living organisms by a number of mechanisms

Sediment is transported along the coast in the direction of the prevailing current (longshore drift). Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of Longshore drift (sometimes known as shore drift, LSD or littoral drift) is a geological process by which Sediments such as sand When the upcurrent amount 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. These banks may slowly migrate along the coast in the direction of the longshore drift, alternately protecting and exposing parts of the coastline. Longshore drift (sometimes known as shore drift, LSD or littoral drift) is a geological process by which Sediments such as sand Where there is a bend in the coastline, quite often a build up of eroded material occurs forming a long narrow bank (a spit). A spit is a deposition Landform found off Coasts. At one end spits connect to land while at the far end they exist in open water armored beaches and submerged offshore sandbanks may also protect parts of a coastline from erosion. Armor, in Hydrology and Geography is the association of surface Pebbles rocks or Boulders with Stream beds or Beaches Most A shoal or sandbar (also called sandbank) is a somewhat Linear Landform within or extending into a body of Water, Over the years, as the shoals gradually shift, the erosion may be redirected to attack different parts of the shore.

Ice erosion

Ice erosion is caused by movement of ice, typically as glaciers. Glaciers erode predominantly by two different processes: abrasion/scouring and plucking. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. Plucking, in the sense relating to Glaciers is when a glacier erodes away chunks of Bedrock to be later deposited as Glacial erratics Glacial plucking In an abrasion process, debris in the basal ice scrapes along the bed, polishing and gouging the underlying rocks, similar to sandpaper on wood. Glaciers can also cause pieces of bedrock to crack off in the process of plucking. These processes, combined with erosion and transport by the water network beneath the glacier, leave moraines, drumlins and glacial erratics in their wake, typically at the terminus or during glacier retreat. Moraine refers to any glacially formed accumulation of unconsolidated glacial debris (soil and rock which can occur in currently glaciated and formerly glaciated regions such as those A drumlin (Irish droimnín, a little hill ridge is an elongated whale-shaped Hill formed by glacial action A glacial erratic is a piece of rock that deviates from the size and type of rock native to the area in which it rests the name " erratic " is based on the whitechuck glacier 2006jpg|right|thumb|320px|The same view as seen in 2006 where this branch of glacier retreated 1

Freeze Thaw is the weathering process in which water trapped in tiny rock cracks freezes and expands, breaking the rock. This can lead to gravity erosion on steep slopes. The scree which forms at the bottom of a steep mountainside is mostly formed from pieces of rock broken away by this means. Scree, also called talus and detritic cone, is a term given to broken rock that appears at the bottom of Crags mountain Cliffs or It is a common engineering problem wherever rock cliffs are alongside roads, because morning thaws can drop hazardous rock pieces onto the road.

In some places, water seeps into rocks during the daytime, then freezes at night. Ice expands, thus, creating a wedge in the rock. Over time, the repetition in the forming and melting of the ice causes fissures, which eventually breaks the rock down.

Wind erosion

Main article: Aeolian processes

Wind erosion is the result of material movement by the wind. Aeolian (or Eolian or Æolian) processes pertain to the activity of the Winds and more specifically to the winds' ability to shape the surface of the There are two main effects. First, wind causes small particles to be lifted and therefore moved to another region. This is called deflation. Second, these suspended particles may impact on solid objects causing erosion by abrasion.

Wind erosion generally occurs in areas with little or no vegetation, often in areas where there is insufficient rainfall to support vegetation. An example is the formation of sand dunes, on a beach or in a desert. In physical Geography, a dune is a Hill of Sand built by Aeolian processes. Windbreaks are often planted by farmers to reduce wind erosion.

Soil Erosion and Climate Change

The consensus of atmospheric scientists is that climate change is occurring, both in terms of global air temperature and precipitation patterns. Climate change is any long-term significant change in the “average weather” that a given region experiences Warmer atmospheric temperatures associated with greenhouse warming are expected to lead to a more vigorous hydrological cycle, including more extreme rainfall events (IPCC, 1995). Karl and Knight (1998) reported that from 1910 to 1996 total precipitation over the contiguous U. S. increased, and that 53% of the increase came from the upper 10% of precipitation events (the most intense precipitation). The percent of precipitation coming from days of precipitation in excess of 50 mm has also increased significantly.

Studies on soil erosion suggest that increased rainfall amounts and intensities will lead to greater rates of erosion. Thus, if rainfall amounts and intensities increase in many parts of the world as expected, erosion will also increase, unless amelioration measures are taken. Soil erosion rates are expected to change in response to changes in climate for a variety of reasons. The most direct is the change in the erosive power of rainfall. Other reasons include: a) changes plant canopy caused by shifts in plant biomass production associated with moisture regime; b) changes in litter cover on the ground caused by changes in both plant residue decomposition rates driven by temperature and moisture dependent soil microbial activity as well as plant biomass production rates; c) changes in soil moisture due to shifting precipitation regimes and evapo-transpiration rates, which changes infiltration and runoff ratios; d) soil erodibility changes due to decrease in soil organic matter concentrations in soils that lead to a soil structure that is more susceptible to erosion and increased runoff due to increased soil surface sealing and crusting; e) a shift of winter precipitation from non-erosive snow to erosive rainfall due to increasing winter temperatures; f) melting of permafrost, which induces an erodible soil state from a previously non-erodible one; and g) shifts in land use made necessary to accommodate new climatic regimes.

Studies by Pruski and Nearing (2002) indicated that, other factors such as land use not considered, we can expect approximately a 1. 7% change in soil erosion for each 1% change in total precipitation under climate change.

Tectonic effects of erosion

The removal by erosion of large amounts of rock from a particular region, and its deposition elsewhere, can result in a lightening of the load on the lower crust and mantle. In Geology, a crust is the outermost solid shell of a planet or moon The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided This can cause tectonic or isostatic uplift in the region. Tectonic uplift is a geological process most often caused by Plate tectonics which increases elevation Isostasy (Greek isos = "equal" stásis = "standstill" is a term used in Geology to refer to the state of gravitational equilibrium between the Research undertaken since the early 1990s suggests that the spatial distribution of erosion at the surface of an orogen can exert a key influence on its growth and its final internal structure (see erosion and tectonics). Orogeny (Greek for "mountain generating" is the process of natural Mountain building and may be studied as a tectonic structural event as a geographical event and The interplay between erosion and tectonics has been a matter of debate since the early 1990s ^[5]

Materials science

In materials science, erosion is the recession of surfaces by repeated localized mechanical trauma as, for example, by suspended abrasive particles within a moving fluid. Materials Science or Materials Engineering is an interdisciplinary field involving the properties of matter and its applications to various areas of Science and Erosion can also occur from non-abrasive fluid mixtures. Cavitation is one example. Cavitation is defined as the phenomenon of formation of vapour bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapour pressure

In hard particle erosion, the hardness of the impacted material is a large factor in the mechanics of the erosion. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force Mechanics ( Greek) is the branch of Physics concerned with the behaviour of physical bodies when subjected to Forces or displacements A soft material will typically erode fastest from glancing impacts. Harder material will typically erode fastest from perpendicular impacts. Hardness is a correlative factor for erosion resistance, but a higher hardness does not guarantee better resistance. Factors that affect the erosion rate also include impacting particle speed, size, density, hardness, and rotation. Coatings can be applied to retard erosion, but normally can only slow the removal of material. Coating is a Covering that is applied to an object The aim of applying coatings is to improve surface properties of a bulk material usually referred to as a substrate Erosion rate is typically measured as mass of material removed divided by the mass of impacting material.

Figurative use

The concept of erosion is commonly employed by analogy to various forms of perceived or real homogenization (i. Analogy is both the cognitive process of transferring Information from a particular subject (the analogue or source to another particular subject (the target and e. erosion of boundaries), "leveling out", collusion or even the decline of anything from morals to indigenous cultures. Morality (from the Latin la moralitas "manner character proper behavior" has three principal meanings The term Indigenous Peoples or autochthonous peoples can be used to describe any Ethnic group who inhabit a geographic region with which they have the earliest historical It is a common trope of the English language to describe as erosion the gradual, organic mutation of something thought of as distinct, more complex, harder to pronounce or more refined into something indistinct, less complex, easier to pronounce or (disparagingly) less refined. See also Figure of speech In linguistics trope is a rhetorical Figure of speech that consists of a play on words i Sound change includes any processes of Language change that affect pronunciation ( phonetic change) or sound system structures ( Phonological change

Origin of term

The first known occurrence of the term "erosion" was in the 1541 translation by Robert Copland of Guy de Chauliac's medical text The Questyonary of Cyrurygens. Robert Copland (fl 1515 English printer and Author, is said to have been a servant of William Caxton, and certainly worked for Wynkyn Guy de Chauliac ( c.1300 &ndash 1368 born in Chaulhac, Lozère, France, was the most eminent of Surgeons during the European Chirurgia magna (Great Surgery (complete title Inventarium sive chirurgia magna) completed in 1363 is a guide of Surgery and practical Copland used erosion to describe how ulcers developed in the mouth. Ulcers are healing wounds that develop on the skin mucous membranes or eye The mouth, buccal cavity, or oral cavity is the first portion of the Alimentary canal that receives food and begins digestion by mechanically breaking up By 1774 'erosion' was used outside medical subjects. Oliver Goldsmith employed the term in the more contemporary geological context, in his book Natural History, with the quote

"Bounds are thus put to the erosion of the earth by water. Oliver Goldsmith (10 November 1730 or 1728 &ndash 4 April 1774 was an Anglo-Irish writer poet and Physician known for his Novel The Vicar "

See also

References

• Pruski, F. F. and M. A. Nearing. 2002. Runoff and soil loss responses to changes in precipitation: a computer simulation study. Journal of Soil and Water Conservation 57(1), 7-16.
• Karl, T. R. and R. W. Knight. 1998. Secular trend of precipitation amount, frequency, and intensity in the United States. Bulletin of the American Meteorological Society 79:231-242.
• IPCC. 1995. Second Assessment Synthesis of Scientific-Technical Information relevant to interpreting Article 2 of the UN Framework Convention on Climate Change. Intergovernmental Panel on Climate Change. Geneva, Switzerland. 64 pp.

Further reading

• Boardman, John; Poesen, Jean (2006). Soil erosion in Europe. Chichester: Wiley. ISBN 9780470859100.  
• Schmittner Karl-Erich and Pierre, 1999. The impact of atmospheric sodium on erodibility of clay in a coastal Mediterranean region. Environmental Geology 37/3: 195-206.
• Montgomery, David R. (2007) Soil erosion and agricultural sustainability PNAS 104: 13268-13272.

External links

• The Soil Erosion Site
• Coastal Erosion Information from the Coastal Ocean Institute, Woods Hole Oceanographic Institution
• International Erosion Control Association
• USDA National Soil Erosion Laboratory
• The Soil and Water Conservation Society
• International Soil Conservation Organization
• Bioerosion website at The College of Wooster
• Pulawy Erosion Research Center
• Southwest Watershed Research Center

The Woods Hole Oceanographic Institution (WHOI is a private nonprofit research and higher education facility dedicated to the study of all aspects of marine science and engineering and

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic