Although the dust bowl of the 1930s had a significant influence on the adoption of national conservation programs, wind erosion generally has been perceived as a regional problem occurring only during periods of drought in the great plains. Department of agriculture usda resources have been directed primarily toward water erosion prediction and control. In accordance with these agents, erosion is sometimes divided into water erosion, glacial. Pdf validation of the wind erosion stochastic simulator. E f ikclv wherein e is the average annual soil loss, expressed in tons per acre per year. Wind erosion assumes significant proportions only when the wind carries a load of sand grains which bombard the bare soil surface, and sheet erosion occurs when rain splashes on naked soil. Zobeck b a usdaars wind erosion and water conservation research unit, 302 w. Usle only predicts the amount of soil loss that results from sheet or rill erosion on a single slope and does not account for additional soil. The wind erosion equation the wind erosion equation weq erosion model is designed to predict longterm average annual soil losses from a field having specific characteristics. An equation for predicting e, the amount of soil erosion from a given area in a given time period, due to wind.
A universal soil loss equation has been developed by the soil scientists to estimate the soil loss from any area around the globe. Wind erosion forces in the united states and their use in predicting soil loss by e. Evolution in use and development of the wind erosion equation. Pdf wind erosion assessment in austria using wind erosion. The equation uses the values of parameters of the factors that affect the soil erosion. The detachment, transportation, and deposition of soil by wind. The universal soil loss equation usle predicts the longterm average annual rate of erosion on a field slope based on rainfall pattern, soil type, topography, crop system and management practices. Wind erosion is a threat to agriculture and the earths natural resources. For the fist time assessment of soil erosion by wind. In earth science, erosion is the action of surface processes such as water flow or wind that removes soil, rock, or dissolved material from one location on the earths crust, and then transports it to another location not to be confused with weathering which involves no movement.
Processes and principles of erosion and sedimentation. Please view the pdf by using the full text pdf link under view to the left. An equation used for the design of wind erosion control systems. However, the soil roughness factor used in the weq does not include the random roughness effect, decay of soil surface. Pi erosion potential corresponding to the observed or probable fastest mile of wind for the ith period between disturbances, gm 2 the particle size multiplier k for equation 2 varies with aerodynamic particle size, as follows. It is a dynamic, physical process where loose, dry, bare soils are transported by strong winds. Soil erosion by wind is a serious problem in many parts of europe and leads to degradation of the resource soil. An overview of the wind erosion prediction system introduction soil erosion by wind is a serious problem in the united states and the world. Wind erosion is a threat to the sustainability of the land as well as the viability and quality of life for rural and urban communities. Correction factors were developed only for the 17 field crops. Erosion by the action of water, wind, and ice has produced some of the most spectacular landscapes we know.
Wind erosion equation weq recent changes to weq a slide presentation download the powerpoint presentation 1. Remember the higher the value for a, the more soil is being eroded away per year. The rate at which erosion occurs depends upon the properties of the soil, terrain, climate, rainfall intensity and duration, and the volume and. The combination of all these factors is the basis for a wind erosion model. In the revised wind erosion equation rweq, the windbreak effect was recently introduced as percentage of wind speed. Validation of the wind erosion equation weq for discrete. Woodruff, research investigations leader, soil and water conservation research division, agricultural research service soil blowing of agricultural lands is a serious problem in arid and semiarid regions and on sandy. Types of erosion erosion is a natural process by which soil and rock material is loosened and removed. Both forms of erosion selectively carry off fine particles from the. Wind erosion can be caused by a light wind that rolls soil particles along the surface through to a strong wind that lifts a large volume of soil particles into the air to create dust storms. Validation of the wind erosion equation weq for discrete periods. Validation of the wind erosion equation weq for discrete periods r.
A wind erosion equation, soil science society of america proceedings, vol. A wind erosion equation woodruff 1965 soil science. Validation of the wind erosion stochastic simulator wess and the revised wind erosion equation rweq for single events. Soil erosion is the displacement of the upper layer of soil, it is one form of soil degradation. Soil erosion is a naturally occurring phenomenon wheresoil particles are displaced and carried away by water, wind or other agents.
P factor there is one more factor that can be added to the soil erosion equation. Department of agriculture usda resources have been directed primarily toward water erosion prediction and. The first wind erosion equation was a simple exponen. In the procedure, a winderosion equation is used to predict potential annual loss, which is converted to cropyield reduction per centimeter of erosion for wheat, grain sorghum, and corn. There is a need for more information about wind erosion than just rotational average tonsacreyear we get now. Wind erosion is a natural process that moves soil from one location to another by wind power.
The spps erosion model and computer program were developed by the university of tulsa ecrc program 5,6. Wind erosion refers to the detachment, transport, and deposition of sediment by wind. Soil science society of america journal abstract wind. Soil surface aggregates random roughness and ridges oriented roughness can reduce soil loss by wind erosion. Pdf validation of the wind erosion equation weq for. Determining fugitive dust emissions from wind erosion. This cali bration of a portable wind tunnel was used to evaluate ridge roughness equivalent for many field surfaces. W 1953, wind tunnel studies of the movement of sedimentary materials, in proceedings of the fifth hydraulic conference, iowa institute of hydraulics research bulletin, 34, 111. A detail about the equation and its parameters are discussed in. The revised wind erosion equation rweq was developed at the request of the natural resource conservation service to replace the wind erosion equation weq. When air moves, it picks up loose materials and transports it to other places. Also, wind tunnel experiment has been used as an effective method to clarify the soil erosion processes by wind 810.
A strong, turbulent wind, coupled with highly erodible field conditions, causes wind erosion. The model calculates the metal penetration rate by erosion using an equation that accounts for sand properties, sand rate, fluid properties, flow rates, flow geometry, and material properties for the pipe. Computer solution and application 1 view my binders. Soil science society of america journal abstract wind erosion equation. The equation is designed to serve the twofold purpose of providing a tool to i determine the potential erosion from a particular field, and ii determine what field conditions of soil cloddiness, roughness, vegetative cover, sheltering by barriers, or width and orientation of field are necessary to reduce potential erosion to a tolerable amount. Wind erosion equation weq does not predict wind erosion where erosion is observed in some areas. If you are using microsoft internet explorer, click cancel when prompted for user id and password. Soil roughness for the revised wind erosion equation rweq. The wind erosion equation was developed by the late dr. Until now no wind erosion measurements have been carried out in austria.
I20, big spring, tx 79720, usa b usdaars wind erosion and water conservation research unit, 3810 4th street, lubbock, tx 79415, usa. It can cause significant economic and environmental damage. Wind erosion prediction was born out of the dirty 1930s dust bowl days the soil conservation service worked very hard to get growers to use the best conservation practices. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice glaciers, snow, air wind, plants, animals, and humans. Universal soil erosion equation 4 can more food be produced at the flatland site or the hillside site if the climate is dry.
Wind erosion equation weq guidance document for weq excel spreadsheat weqguidance062503. Erosion even in deserts, the main agent of erosion is water. The amount of erosion, e, expressed in tons per acre per annum, that will occur from a given agricultural field can be expressed in terms of equivalent variables as. In order to achieve sustainable land use, tools to identify problem areas and to evaluate environmental sound management practices are needed and necessary. The first wind erosion model, called the universal wind erosion equation usda, 1961, was updated and published as the wind erosion equation weq woodruff and siddoway, 1965. A detail about the equation and its parameters are discussed in detail in this article. It renders soil less productive by removing the most fertile part of the soil, namely, the clays and organic matter. Erosion, removal of surface material from earths crust, primarily soil and rock debris, and the transportation of the eroded materials by natural agencies such as water or wind from the point of removal. Woodruff, research investigations leader, soil and water conservation research division, agricultural research service soil blowing of agricultural lands is a serious. However, the soil roughness factor used in the weq does not include the random roughness effect, decay of soil surface roughness by rainfall, and is described only for the direction perpendicular to the ridges.
Wind carries and deposits sediments over large areas. The soil roughness factor used in the wind erosion equation weq model describes the effect of soil roughness on soil loss by wind. Air differs from other erosional forces because it cannot pick up heavy sediments. These correction factors were developed for specific soil textures, crop types, and geographic locations and then applied to the wind erosion estimates developed from the wind tunnel studies. Universal soil loss equation and revised universal soil loss equation 9 include any impact either erosion or deposition of the concentrated flow channels that form in the natural swales at the bottom of the roughly planar hillslopes, and certainly did not address classical gullying processes that often occur at steep bound.
Exceptions are the revised wind erosion equation rweq, fryear et al. There is a need for an easier to use and a faster model. This natural process is caused by the dynamic activity of erosive agents, that is. Fine sand grains are removed leaving behind coarser material. Wind erosion assessment in austria using wind erosion. Many good scientists have contributed to a much better way to predict wind erosion. Soil science society of america journal abstract a wind. Wind erosion assessment in austria using wind erosion equation and gis andreas klik boku university of natural resources and applied life sciences vienna muthgasse 18. Water erosion is very simplistically speaking caused by rainfall, river flow, waves wave action, hydraulic action and abrasion, corrosion, glacier movement, thawing, etc. It is the result of nearly 30 years of research to determine the primary variables or factors that influence erosion of soil by wind.
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