When a lot of rain falls in a short period of time, much of the water is unable to soak into the ground. Water Erosion. Wind erosion is caused by the action of the wind on the soil surface and is the process by which fine soil particles are carried away. Specialized erosion control practices have been developed for use within stream channels, forest areas, and construction sites. Fig. Get premium, high resolution news photos at Getty Images It can consider processes, such as infiltration, sediment transport and deposition, evaporation, transpiration, snow melt, residue and canopy effects on soil detachment, and contour effects. For details, reference may be made to Lane and Nearing (1989). As the wind blows, soil particles are dislodged and begin to roll or bounce along the soil surface in a process called saltation. "The erosion of the terrestrial surface"(2017) Educational Astronomy. In the WEPP erosion model, the interrill sediment delivery is adjusted to account for the effects of ground cover, dead roots, live roots, and canopy cover. One of the most effective means of reducing erosion is to maintain a vegetative or residue cover on the soil surface. The function for interrill sediment delivery also includes terms to account for ground and canopy cover effects, which are discussed below. Secondly, these particles, when detached, move downhill with the layers of water that flow by dragging sediments. Ground Water Erosion and Deposition. This emphasizes the need for careful site selection, a thorough documentation of soil and site conditions as well as a sufficient number of experiments to achieve statistically significant and spatially representative results. Water erosion is caused by the detachment and transport of soil by rainfall, runoff, melting snow or ice, and irrigation. As in the case of water erosion, models that examine the factors important in wind erosion are useful in predicting wind erosion (Saxton et al., 2000). This criterion is considered as ‘more is better.’, By each alternative, the needs of WR have been considered. It should be noted that finer textured soils (those with more silt and clay sized particles) are often less erodible than sandy soils. The kinematic wave equations for one-dimensional overland flow are: where h is the local flow depth (m); t is the time (s); q is the discharge per unit width (m2/s); x is the distance down the plane (m); r is the rainfall intensity (m/s); f is the infiltration rate (m/s); v is excess rainfall rate (m/s), and α is the depth – discharge coefficient (m0.5/s). Rainfall characteristics, soil factors, topography, climate, and land use are important elements affecting soil erosion. "Erosion"(April, 2011) in Ecology Today Retrieved from: ecologiahoy.com. Studies have shown that raindrops fall at speeds of up to 20 mph and can shed particles of earth up to a distance of one and a half meters horizontally and half a meter vertically. In case there is a reservoir within the catchment, the same can also be considered. This drag can occur diffusely (barely perceptible) or even. (2017) Retrieved from: vanderbilt.edu. In general, erosion is the erosion of the earth by forces such as water, wind and ice. The output of the continuous simulation model represents the time-integrated estimate of erosion. 12.10. These results confirm the hypothesis that wind-driven rain potentially produces an increase in soil erosion rates. The WEPP watershed model is made up of four major components: hillslope, channel, impoundment, and irrigation. The criteria were rated on a 1–10 scale, according to local evaluations and other methods of elicitation. where Vf(m/s) is the effective fall velocity for the sediment, and q (m2/s) is the discharge per unit width. (2006) Aquatic Ecology (Dec. 2006), Volume 40. 4. Erosion starts with weathering. Water erosion, in general, causes an estimated loss of four billion tons of land each year. Rainwater harvesting is the practice of collecting and storing rain for reuse, rather than letting the water run off and be absorbed into the ground or channeled into drains, streams, or rivers. The pictures taken in Sampford Peverell, Devon, show severe soil erosion on a steep field that was said to have contained too few crops prior to the heavy winter rain. Both are effectively stopped by an erosion mat. The water erosion rates observed during six simulated sequences that involved 18–30-min rainfalls during the Jutland field campaign of 2011 are presented in Fig. Conservation measures that have been effectively used to reduce soil erosion on agricultural areas include contouring, strip cropping, conservation tillage, terraces, buffer strips, and use of polyacrylamide on irrigated areas. Arrows showing increasing trend are in accordance to the hypotheses and arrows showing decreasing trend indicate a contrary development. The model requires huge data on various variables for a good implementation; the required climatic data includes rainfall, its peak and duration, temperature data, wind velocity and direction, solar radiation, snowfall and snowmelt. The channel erosion and grid erosion is modelled using hydraulic concepts. J.B. Grau, ... J.J. Martín, in Encyclopedia of Agriculture and Food Systems, 2014. One of the causes is water. This reflects the ability of fine particles to form soil large aggregates that hold the soil in place during high wind events. Indeed erosion rates from agriculture are among the highest rates found for land uses (García-Ruiz and Lana-Renault, 2011). The irrigation component calculates erosion and deposition on border irrigation areas. Rainfall – Rainfall can cause erosion when the rain hits the surface of the Earth. Weathering also impacts artificial (human-made) objects, and even our human bodies directly. Erosion has helped to form many notorious characteristics of the surface of the Earth, including mountain peaks, valleys and coasts. Vanderbilt's Online Research Magazine. 5.1.4. Rainwater harvesting (RWH) is the collection and storage of rain, rather than allowing it to run off. This criterion is considered as ‘more is better.’. The WEPP erosion model uses a steady-state sediment continuity equation to describe the downslope movement of suspended sediment in a rill: where x (m) represents the distance downslope, G (kg/s/m) is the sediment load, Di (kg/s/m2) is the lateral sediment flow from the interrill areas, and Df (kg/s/m2) is the rill erosion or deposition rate. A watershed must be represented by at least one hillslope element. If allowed to continue, loss of vegetation, habitat and land will occur. Have been established taking into account actors' opinions (Grau, 2003). Singh, in Developments in Water Science, 2003. Given that the erosion driving rainfall was almost equal during each test, the low soil loss observed during FOU 3 indicates that soil resistance to erosion has a strong control over wind-driven rain on the Jutland sands. (2015) presented an analysis of published data on soil erosion rates (in units of mass per area and time), considering about 4000 sites worldwide. Wind and water erosion are the main soil deterioration processes in different zones. Plus rain water makes temporary river streams that cause erosion too. How to Prevent Water Erosion. Depending on the type of force, erosion can occur rapidly or require thousands of years. In the WEPP watershed model, hillslope elements can contain up to 10 overland flow sub-elements which may represent changes in cropping patterns (strip cropping), soil variation in the downslope direction, different land use patterns, or changes in grazing intensities. This section introduces you to weathering and erosion, both important parts of the rock cycle. The hillslope component is the WEPP hillslope model which calculates erosion and deposition on rill and interrill flow areas. A drop of six millimeters weighs 216 times more than a drop of a millimeter. ), P. Tarolli, ... Wenfang CAO, in Encyclopedia of the Anthropocene, 2018. Surface residue, for example, plays an important role in terms of predicting the amount of soil lost during a given rainfall event. This is called splash erosion. You will learn how different rocks are weathered and eroded and the implications of this weathering. This causes laminar erosion, as raindrops give off soil particles by the effect of kinetic energy. There are two stages of sheet erosion. An erosion model may use a plant growth and residue decay model to estimate the amount of crop residue present on the soil surface for each day through the year. The berm will keep the water in the rain garden, so has to be well-compacted, around 30cm (1ft) wide and 10cm (6in) in height Leave a notch in the berm, with a gravel-filled channel for the water to exit into a conventional drainage system If the area is sloping, the top … The channel component calculates erosion and deposition within concentrated flow areas which can be represented as permanent channels or ephemeral gullies. Whether you’re worried about erosion due to rain, a nearby river, or your irrigation system, it is a concern that many homeowners and business owners have, even in Bakersfield. Wind and water erosion are not the only means by which soil can be moved beyond the boundaries of a field. It predicts where deposition begins and/or ends on a hillslope, which may vary from storm to storm. Gradual threats. An impoundment element can receive input from hillslope or channel elements. When mixed with the water of the drops and, as the water sinks in the soil, these particles clog the pores in the soil that normally absorbs the rainwater. For that, they have considered this criterion as of the ‘more is better’ kind. Instead, it runs over the land. Using Barriers to Control Erosion Know that barriers are best left to professionals. Representation of watershed in WEPP erosion model. In addition, heavier droplets travel at speeds higher than small droplets. Rainwater and sea water can act as weak acids. The high variability of results caused by the soil conditions presents a strong contrast to the controlled rainfall applied to the plots. Fig. The University of Maryland University College notes that one inch of rain water running off from the roof of a 1,500 square foot building produces 935 gallons of water. Water causes erosion through rainfall, rivers, ocean waves, or large floods. The concepts of stochastic weather generation, infiltration theory, hydrology, hydraulics, soil physics, plant science, and erosion mechanism have been used in this model. Some water from the rain is evaporated or soaked up by plants other parts of the rain sinks into the soil. A hillslope element can drain into a channel either at the headwaters or laterally, or into an impoundment. Although generally convincing, test sequence number three (FOU 3) shows that other factors are able to reduce erosion almost entirely. Certain points on the hillslope may experience detachment during some rainfall events and deposition during other events. Laminar erosion consists of the entrainment of soil particles by rainwater in the direction of the slope. J.E. Similarly, it is known as rain erosion to a form of water erosion caused by rain. The model calculates both detachment and deposition. Interrill sediment delivery, and Di, is considered to be independent of x. Rill erosion, Df, is positive for detachment and negative for deposition. Liquid water is the major agent of erosion on Earth. The drops fall in sizes that reach up to six millimeters in diameter. Dr Favis-Mortlock, D."Soil Erosion by Water"(April 2017) The Soil Erosion Site. García-Ruiz et al. As we write this article spring rains are coming hard and fast causing substantial soil erosion when soils are most vulnerable because of degraded crop residue cover, soil preparation by tillage and no crop canopy. Water erosion may occur within rills, interrill areas (the regions between rills), gullies, ephemeral gullies, stream channels, forest areas, and construction sites. Representation of hillslope in WEPP erosion model. Methods to control or reduce wind erosion are covered in Chapter 20. Smaller particles remain suspended in air for longer periods of time and are therefore more likely to travel much longer distances. Once the unsteady flow calculations are made to get the runoff peak rate and duration, quasi–steady state flow is assumed at the peak rate and is partitioned into broad sheet flow for interrill erosion and concentrated flow for rill erosion. These channels, when united, create other even larger channels, which progressively form grooves, ditches and, finally, larger caverns called"gullies". Date Published: May 25th, 2018 . Water droplets in their downward path impact the ground and pluck particles, generating a tiny form of laminar erosion. They separate the particles from the soil and destroy their structure. The overland flow hydrograph is developed by assuming broad, uniform sheet flow. Sediment delivery from the interrill areas is considered to be proportional to the square of rainfall intensity, with the constant of proportionality being the interrill erodibility parameter. The CO 2 combines with water to form carbonic acid. According to Montgomery (2007), cultivated fields from different regions mostly erode at rates typical of Alpine terrains. Prediction of the effects of land use and management practices on erosion control are perhaps the most important part of an erosion prediction tool if the purpose is to plan land and farm management systems to control erosion. Copyright © 2021 Elsevier B.V. or its licensors or contributors. The WEPP landscape profile version model requires four input data files: a soil file, a slope profile file, a crop management file, and a climate file. Specifically the model considers three erosion processes: detachment, transportation and deposition. About 95% of soil is splashed by falling rain drops and runoff water erodes less than 5% of the soil. The erosion done by water is called ablation. We use cookies to help provide and enhance our service and tailor content and ads. Erosion caused by run-off rain water near Ponta d'Ana, Algarve, Portugal. Water erosion is the removal of soil by water and transportation of the eroded materials away from the point of removal. It is also known as raindrop erosion. J.F. The main consequences are a loss of cultivable, fertile land, soil structure degradation, destruction of infrastructures, pollution of surface water, flood risk, etc. WEPP model may also be executed in a single-storm mode, although it is very effective when used as a continuous simulation model. Soil erosion by water (aka 'water erosion') is the result of rain detaching and transporting vulnerable soil, either directly by means of rainsplashor indirectly by rill and gully erosion. These soil surfaces are not exposed to the constant hydraulic forces of rivers and channels, but the occasional wetting and drying erosion forces from wind, rain and gravity. The theory of the model has been described in detail by Finkner et al. If the area is on a slope, however, unabsorbed water begins to flow downhill into a thin layer, dragging soil particles that have been loosened by the bombardment of raindrops. Therefore soil wind erosion and soil texture are not always directly related. Like water erosion, wind erosion has two phases: detachment and movement. For the case of rill detachment, where Dc is the detachment capacity by flow and Tc (kg/s/m) is the sediment transport capacity in the rill. S.K. For some locations, diverting this water is necessary to prevent soil erosion and to prevent chemicals and … Water is the main cause of erosion on Earth, being one of the most powerful forces on the planet. The severity of wind erosion is influenced by wind speed, the condition of the soil surface, and the amount of vegetation cover present. Rills are the shallow drainage lines that are … Conservation Measures. When the water accumulates on the surface and increases the speed with which it drains, a network of small channels is formed. Lobb, in Encyclopedia of Ecology, 2008. Núñez Solís, J. Rainfall, and the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, and gully erosion. This criterion has been considered as of the ‘more is worst’ kind. They have been considered in each subzone. The relative WE indexes figure in the IM. The main aim was to employ the current knowledge to develop a model as an alternative to USLE. Retrieved from: astromia.com. If the erosion on … Water is an object that is powerful enough to move materials that are in the ground or on the surface of the soil. Water erosion occurs when rainfall breaks soil aggregates causing detachment and displacement of soil, either directly by means of raindrop impact or indirectly through large bodies of water. 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Kuhn, ... Wolfgang Fister, in, Soil Movement by Tillage and Other Agricultural Activities. Rainwater capture and storage system at the modern heritage property. The erosion is very apparent when the walls are inclined. The Rain erosion Is the manifestation of the action of rain on the earth's surface. A conceptual representation of a hillslope and a watershed for application of WEPP are shown in Fig. Water action due to rain erodes the soil and causes activities like gully, rill, and stream erosion leading to the downstream effects of flooding and sedimentation. Laminar erosion develops in two stages. As a result, the soil becomes crusty and impermeable. Erosion by Runoff. The figures included in this criterion have been obtained from the results of different forums and meetings with institutions, organizations, and native people (Grau, 2003). A brief description of the model is given here. On the other hand, air pollution is measured using the PM10 standard, which consists largely of silt-sized particles, and the PM2.5 standard, which captures mainly clay size particles. All these types of flowing water can cause erosion and deposition. C. Longjun, in Encyclopedia of Environmental Health (Second Edition), 2019. 12.11. Interrill erosion is conceptualized as a process of sediment delivery to rills, whereby the interrill sediment is either carried off the hillslope by the flow in the rill or deposited in the rill. Fig. The profiles are at or near saturation. 12.10 and 12.11. For example, hills and ridges formed by erosion tend to have smoothly rounded ridges that are distinct from the sharper profiles created by other forms of water erosion. Eight criteria have been applied following field research, expert panels, social investigation, and personal interviews. As it increases, erosion by gullies, can also cut below the groundwater level. While it is mainly caused by rainfall, inter-rill erosion can be accelerated by factors such as gradient, topography, vegetative cover, and climate. Retrieved from: Springer Link link.springer.com. Erosion by water begins with a drop of rain. "Rain Erosion Damages"(2017) Poly Tech A / S Recovered from: ainerosion.com. Under the pressures of overgrazing, deforestation, and irrational reclamation for agriculture production purpose, vegetation was degraded and destroyed in desertification-prone land areas, steppes were overgrazed and degraded in large quantity, soil was salinized and deteriorated, and soil/water conservative capacity was reduced and lost in many affected developing countries due to floods, drought, and other natural disasters. In five out of six cases, erosion during the third run, which includes the influence of wind on raindrops, was significantly increased compared to the second rainfall without wind. This water that travels across the land is called runoff. Rain erosion is one of the different types of water erosion, among which are also listed: laminar erosion, furrow erosion, erosion in gullies and erosion in terracotta. The model uses a daily time step and simulates the process of plant growth, soil properties and hydrologic processes. The Erosion of Reinforced Concrete Walls by the Flow of Rainwater Kawthar Hadja, and Fattoum Kharchi* (Received February 26, 2016, Accepted October 24, 2016, Published online February 28, 2017) Abstract: The action of rainwater on reinforced concrete walls has led to an erosion phenomenon. "What is rain splash erosion and why is it important?"Exploration. Retrieved from: soilerosion.net (2017) England. Among the cultivated lands, vineyards deserve a particular attention because, aside from representing one of the most important crops for income and employment, they also have proven to be the form of agricultural use that causes one of the highest soil losses (Prosdocimi et al., 2016). Now imagine when heavy rain falls, millions of rain drops fall on the soil for many days, causing considerable soil erosion. Action appropriate to risk. The authors have considered that it would be satisfactory to give employment to the majority of the population. Such an erosion, where a bit of soil is scraped away, due to each falling raindrop, is called Splash erosion. The relative results have been taken into the IM for this criterion. For the case of deposition. The impoundment component calculates deposition of sediment within terrace impoundments and stock tanks. As the water travels it takes the soil particles with it. The amount of soil loss is related to the soil texture and moisture content as well as the method of harvesting. Inter-rill erosion describes the movement of topsoil by rainfall and its resultant surface flow. Rainfall produces four types of soil erosion: splash erosion, sheet erosion, rill erosion, and gully erosion. There are many different forces in nature that cause erosion. Soil eroded in agricultural landscapes can also be delivered to the drainage network (Borselli et al., 2008), with direct consequences on the rates and magnitudes of floodplain sedimentation (Doolittle, 2006; Knox, 2006). Excessive erosion can threaten the production of agricultural and forest products. The mountain slope model simulates the erosion process from different types of land uses and treatment. The flow of water underground is ground water. They can also cause erosion when raindrops gather together and flow like small streams. Factors Affecting Soil Erosion Caused By Water 3. By continuing you agree to the use of cookies. Erosion may also impact water conveyance and storage structures, and … If a coastline is made up of rocks such as limestone or chalk, over time they can become dissolved by the acid in the water. Many deep-rooted plants, which protect the soil from erosion, depend more on groundwater than on surface water. Rainfall erosion is caused by the detachment and movement of particles from the thin soil caused by the impact of raindrops on the ground. During rainfall, soil splashes due to the impact of rain drops. This means that large droplets carry hundreds of times more energy than droplets. A channel element can receive water and sediment input from hillslope elements, upstream channel elements (up to three channel elements), or an impoundment. Firstly the mats have high surface cover to prevent the rain drops from pounding into the soil. Excessive erosion can threaten the production of agricultural and forest products. The model simulates erosion for some number of years and sums the total soil loss over those years for each point on the hillslope to obtain the average annual values of erosion along the hillslope. The environmental impacts (EI) have been calculated according to Gómez Orea (1999). Larger soil particles can move relatively short distances in this way, but, more importantly, as the large particles bounce and strike smaller particles and aggregates, they provide the energy necessary to break aggregates apart and suspend smaller particles in the air. Soil water erosion on cultivated lands represents a severe threat to soil resources in the world, and especially in Mediterranean areas, due to their topographic, edaphic, and climatic conditions (Prosdocimi et al., 2016). Rainfall erosion is caused by the detachment and movement of particles from the thin soil caused by the impact of raindrops on the ground. If the area is flat, puddles begin to form. In this case, the output represents an average of the erosion events. Gravity causes the water to flow from higher to lower ground. The net soil detachment in rills is calculated for the case when hydraulic shear stress exceeds the critical shear stress of the soil and when sediment load is less than the sediment transport capacity. "Management and Conservation of Soils"EUNED Editorial State University Distance (2001) Costa Rica. From the mechanical point of view, work must be done to erode soil and the source of energy to perform this work must be from rain drop impact and runoff in the water erosion process. 4 shows an example of soil erosion in a vineyard located in Spain.