A view of rill 1 and gully 2 in the study area in this study by using field surveying and many observations, measurements of gullies, rills, and pedestals were recorded. Application of gully and rill erosion indicators for estimating soil loss using gis techniques case study. The channels are shallow enough that they are easily obliterated by tillage. Rill erosion department of primary industries, parks. Channel erosion results from concentrated water flow. What is the difference between rill erosion and gully. Rill erosion is best minimized by minimizing sheet flow, such as by maintaining crop residues and utilizing cover crops. Figure ts14p6 ephemeral gullies and severe sheet and rill erosion in unprotected northwestern ia field gullying processes in streams. Physical barriers, such as terraces, and vegetative barriers can be effective in stopping or reducing rill erosion.
Application of gully and rill erosion indicators for. Unlike sheet an d rill erosion, which occurs as a result of the impact of raindrops and water flowing on the soil surface, ephemeral gully erosion occurs as a result of concentrated flow of surface runoff along a defined channel, and also by subsurface flow by seepage and flow through preferential pathways. Wind or water erosion is the physical wearing of the earths surface. Rill erosion is often described as the intermediate stage between sheet erosion and gully erosion. Detachment in a rill occurs if the sediment in the flow is below the amount the load can transport and if the flow exceeds the soils resistance to detachment. Sheet, rill and gully erosion can be controlled by keeping runoff velocities slow. Once a rill is established, it may soon form a deeply incised erosion gully, like that shown here. A case study in a small catchment of a marginal olive grove article pdf available june 2015 with 601 reads how we measure reads. Towards an assessment of the ephemeral gully erosion. The severity of gully affected area has also been well noted at national and regional levels. Rill erosion small channels on a slope caused by concentrated runoff. Laboratory experiment and theory analysis of dynamic. Soil erosion sheet, rill and wind erosion detachment and transportation of soil particles caused by rainfall runoffsplash, irrigation runoff, or. The channels are shallow enough that they are easily obliterated.
Results from the latter mentioned spatial inventories confirm that erosion is a major soil degradation problem in south africa. Prevention is better than cure 2012 nile basin initiative eastern nile subsidiary action program ensap eastern nile technical regional office entro. The following state costshare practices are designed to address this concern. Less commonly, dissolution of limestone and other soluble rocks by slightly acidic rainfall and runoff also results in the formation of rill like features on the surface of the rock.
Gully erosion over time actually lose less soil than sheet and rill erosion gully erosion can spell big problems for farmers because the affected land is not able to be used for growing crops, and the big ditches create a hazard for the farmer driving his farm machinery over the fields. The four types or mechanisms of erosion are rill erosion, gully erosion, stream bank erosion, and sheet erosion. What is the difference between rill and gully erosion. Gully erosion, a rill channel becomes broader and deeper. Gully depth is often limited by the depth of the underlying rock which means gullies are normally less than 2m deep. Extensive rill systems now occupy steep slopes previously covered with a deep litter horizon. So, if it were to rain, erosion on construction sites would occur in three different ways. Three topographical approaches to survey soil erosion on a. Introduction ike in agricultural plots, erosion on roads is based on the concept of transport capacity of running water, and the deposition that occurs when the transport capacity is exceeded. Gully erosion can also start as a rill a shallow cut in the landscape usually steepsided and v shaped, which expand by ongoing erosion to form a gully. Water induced soil erosion, relating to improper land management, is a serious land degradation problem in ultisols that results in rill and gully erosion. Characteristics and importance of rill and gully erosion cig 41 1, 2015, p. In this case, or where sheet and rill erosion will be controlled with other practices such as residue management, discrete barrier sections may be installed across concentrated flow areas to control ephemeral gully development.
Pdf measurements of gullies and rills were carried out in an olive orchard microcatchment of 6. Sheetrill and gully erosion missouri department of. Rill erosion is usually linked with sheet water driven erosion as the shallow flows of water driving sheet erosion tend to coalesce and thus increase both in velocity and scouring capacity. Some estimates claim rill flow has a carrying capacity of nearly ten times that of non rill, or interrill, areas. There are five types of water erosion shown in figure 2. Dsl1, permanent vegetative establishment grass seeding assistance is authorized for lime and fertilizer, eligible seed, seeding operation and seedbed prep. In the first phase of experiment, rill gullies were mapped based on field survey and rill gully. In splash erosion, the impact of a falling raindrop creates a small crater in the soil, ejecting soil particles. Compare and contrast rill and gully erosion answers. However, when people allow overgrazing or clear land for agriculture, erosion can be introduced into new areas.
The magnitude of piping in the study area is at least three orders of magnitude higher than surface erosion rates i. When used to control only ephemeral erosion, barriers do not need to extend across the ridge tops but. The utm coordinates of each erosion type with higher erosion intensities such as rills and gullies were inserted in gis using gps data. At the same time, the gully becomes deeper and wider because of channel erosion. Gross erosion includes sheet, rill, gully and channel erosion, and is the first step in the process of sediment delivery. Monitoring soil erosion in south africa at a regional scale. One of the most notable aspects of gully erosion is that the newly formed gully bed normally has. These can be very difficult to mitigate, requiring a lot of hand work. Rill erosion is considered in the rusle calculations. Apr 28, 2017 sheet, rill and gully erosion sujeet singh. Rill erosion is most problematic in low cohesion materials, like sand. Gully erosion refers to the cutting of narrow channels called gullies. 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. The splash effect also increases compaction and destroys open soils structure.
Several approaches to erosion and deposition modeling have been developed since 1950s. Sheetrill and gully erosion missouri department of natural. The tons of soil loss can then be determined by multiplying the volume. Even though rill erosion is not as extensive a problem as gully erosion, there are situations in which rills can transform into gullies. Conventional tillage or the notill method may be used for. Pdf assessing the performance of check dams to control rill. Channel erosion is usually subdivided into rill and gully erosion. Types of erosion splash,sheet,rill and gully erosion. Rill erosion is a type of erosion that results in small, yet well defined streams. In general, an ephemeral cropland gully is larger than a rill and smaller than a gully. Follow report log in to add a comment what do you need to know. Pdf characteristics and importance of rill and gully.
In cultivation or pastures, advanced rill erosion can develop into gully erosion. The rill and gully system has fundamentally altered the hydrology of the upper watersheds, greatly decreasing time to peak runoff and significantly increasing stormflow. Each year the rills slowly increase in number become wider and deeper. Rill erosion department of primary industries, parks, water.
Rill and gully erosion risk of lateritic terrain in southwestern birbhum district, west bengal, india v. Rill erosion is the detachment, entrainment, and transport of soil particles by water from small, welldefined channels. What is the difference between rill erosion and gully erosion. Ephemeral and classic gully erosionworksheet forms of erosion by water include sheet and rill, ephemeral gully, classic gully and stream bank. Soil erosion on mountain trails threaten the sustainability of soils and vegetation. The erosion created by these forces increases the size of the rill while also swelling its output volume. Pdf characteristics and importance of rill and gully erosion. There is a wide theoretical knowledge about the effects produced by mountain recreational activities, but particularly for soil erosion there is a shortage of field data. Rill and gully formation following the 2010 schultz fire.
Gully erosion large channels on a slope caused by intense runoff. Classic gully erosion generally occurs in well defined drainage ways and generally is not obliterated by tillage. Gully erosion can also start as a rill a shallow cut in the landscape usually steepsided and vshaped, which expand by ongoing erosion to form a gully. Amongst the three forms, rill erosion remains the main cause for concern. Erosion is not always readily visible, even when soil loss exceeds unsustainable. This type of erosion is calculated by rusle2, the water erosion prediction equation. Types of erosion environment, land and water queensland. As the flow becomes deeper the velocity increases detaching soil particles and scouring channels up to 30cm deep.
Ahmadic a assistant professor, islamic azad university of ardestan, ardestan, iran. Sheet erosion the removal of a thin layer of soil over a large area. This type of erosion is highly visible and affects soil productivity, restricts land use, and can damage roads, fences and buildings. Once a rill is established, it may soon form a deeply incised erosion gully, like that shown. Gully erosion is the removal of soil along drainage lines by surface water runoff. Effects of erosion control practices on nutrient loss. As it is known by many, gully erosion is the worst form of erosion that apart from snatching fertile lands is the main source of sediment load arriving at reservoirs.
In terms of gully erosion, the northern cape 160 885 ha and eastern cape 151 759 ha. As you can see, rills that begin at the top of a slope can quickly disintegrate and branch off into their wider gully. However, in rill and gully erosion, the soil loss is caused by the intense action of a. Soil erosion control measures that increase soil shear strength e. Characteristics and importance of rill and gully erosion. Rill erosion definition earth science the earth images. Erosion caused by concentrated flow begins where overland flow converges to channelized flow conditions.
In some cases, a main gully channel may become as long as one kilometer. There are 4 water erosion estimator types to choose from. Soil erosion sheet, rill and wind erosion detachment and transportation of soil particles caused by rainfall runoffsplash, irrigation runoff, or wind that degrades soil quality. If sheet erosion uniform removal of soil like a thin covering from large area occurs with full force, the run off water moves rapidly over the soil surface cutting well defined finger shaped groove like structure. Because much eroded sediment is deposited in or near the field of origin, only a fraction of the total eroded soil from an area contributes to sediment yield from a watershed. Rill erosion is the removal of soil through the cutting of many small, but conspicuous, channels where runoff concentrates. Although rills are small, they transport significant amounts of soil each year. Each type is associated with the progressive concentration of runoff water as it moves downstream. Laboratory experiment and theoretical analysis of dynamic parameters for water erosion prediction model zhang, q. Rill erosion is the removal of soil by concentrated water running through little streamlets, or headcuts. Splash and sheet erosion can best be prevented by protecting the land surface with vegetation, mulch or erosion control blankets. A more or less uniform layer of fine particles is removed from the entire surface. Sheet erosion is the planar removal of surface soil by the action of either raindrop splash, shallow flows of surface of water, or even by wind. These rills are usually smoothened out every year while forming.
In sheet erosion a thin layer of the surface is removed. Sheet erosion, 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. Methodology the present study is the outcome of intensive field survey. In some situations, headcuts are present and aid in advancing the gully upstream. It happens when water from rainfall does not soak into the soil, but runs across it instead. The soil loss from concentrated flow, gullies, and other similar types of erosion can be determined by calculating the volume of soil removed from the eroded area. Sheet, rill and gully erosion is the unwanted removal of soil from the land surface or through incised channels by the action of rainfall and runoff. Rill erosion represents the intermediate process between sheet and gully erosion. Gully erosion gullies are channels deeper than 30cm that cannot. Channel erosion along gully beds is the main cause of land slides on gully banks.
In rill erosion finger like rills appear on the cultivated land after it has undergone sheet erosion. Application of gully and rill erosion indicators for estimating soil. Inherent to the size of the standard plot, usle only predicts soil loss from interrill and rill erosion wischmeier and smith, 1978. Less conspicuous, but often even more detrimental to crops is the gradual removal of the topsoil layer sheet erosion. Splash erosion, sheet erosion, rill erosion, and gully erosion are natural processes. Rills can follow tillage marks, or they may develop much like a drainage network of rivers in a large basin foster, 1986. Modeling erosion from erosion features on gravel roads. Hydroseeding using fescue and wildflower mixes are commonly applied to graded slopes for erosion control. Field experimental study was conducted to observe the effectiveness of check dams for reducing runoff and sediment yield in small gully catchment area. Protecting the soil from runoff stops potential land degradation and assists with water quality protection. Note that ephemeral gullies and severe sheet and rill erosion persist above some of the waterways. Rill erosion can be reduced by reducing the volume and speed of surface water with grassed waterways and filter strips, ripped mulch lines, and contour drains. Many ephemeral gullies that develop within croplands are tillage induced, as farmers tend to.
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