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United States Department of Agriculture

Agricultural Research Service

Soil Resources & Air Quality Affected by Wind Erosion and Fugitive Dust Emissions
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Wind Erosion - The Problem

Wind erosion is a serious threat to food security and contributes to the degradation of a sustainable agriculture in the United States and throughout the world. In addition, dust storms affect air quality and airborne dust has significant economic, health, ecological, and hydrological impacts.  Soil erosion is by wind is worse in arid and semiarid regions.  Areas most susceptible to wind erosion on agricultural land include much of North Africa and the Near East; parts of southern, central, and eastern Asia; the Siberian Plains; Australia; northwest China; southern South America; and North America.

During the 1930's, a prolonged drought culminated in dust storms and soil destruction of disastrous proportions. The "black blizzards" of the resulting Dust Bowl inflicted great hardships on the people and the land.

DUST BOWL MEDIA REFERENCES 

Over seventy years after the Dust Bowl ended, wind erosion continues to threaten the sustainability of our nations' natural resources. As recently as the spring of 1996, wind erosion severely damaged agricultural land throughout the Great Plains. On cropland, about 70 million hectares (171.8 million acres) are eroded by wind and water at rates that exceed twice the tolerance level for sustainable production (USDA, 1989). On average, wind erosion is responsible for about 40 percent of this loss (Hagen, 1994), and can increase markedly in drought years (Hagen and Woodruff, 1973). In the United States, wind erosion is the dominant problem on about 30 million hectares (73.6 million acres) and moderately to severely damages approximately 2 million hectares (4.9 million acres) annually (USDA, 1965). According to the 1992 National Resources Inventory (NRI), the estimated annual soil loss from wind erosion on nonfederal rural land in the United States was 2.5 tons per acre per year (SCS-USDA, 1994). This number is a decrease from 3.3 tons per acre per year in the 1982 NRI. However much of this reduction was a result of enrollment of land classified as highly erodible in the Conservation Reserve Program (CRP). The CRP enrollment for much of this acreage is scheduled to retire within the next few years.

Wind erosion physically removes the lighter, less dense soil constituents such as organic matter, clays, and silts. Thus it removes the most fertile part of the soil and lowers soil productivity (Lyles, 1975). Lyles (1975) estimated that top soil loss from wind erosion causes annual yield reductions of 339,000 bushels of wheat and 543,000 bushels of grain sorghum on 0.5 million hectares (1.2 million acres) of sandy soils in southwestern Kansas. This loss in productivity has been masked or compensated for over the years by improved crop varieties and increased fertilization. Thus wind erosion reduces potential soil productivity and increases economic costs. Blowing soil impacting plants can also reduce seedling survival and growth, depress crop yields, lower the marketability of vegetable crops, increase the susceptibility of plants to certain types of stress, including diseases, and contribute to transmission to some plant pathogens (Armbrust, 1982 and 1984; Claflin, et al., 1973; Michels et al., 1995). In the long run, the cost of wind erosion control practices can offset the cost of replanting a blown out crop. Some soil from damaged land enters suspension and becomes part of the atmospheric dust load. Dust obscures visibility and pollutes the air, it fills road ditches where it can impact water quality, it causes automobile accidents, fouls machinery, and imperils animal and human health (Skidmore, 1988). In Seward County Kansas alone the state highway department spent over $15,000 in 1996 to remove 965 tons of sand from 500 feet of highway and ditch (Tri-County Area Proposal for EQIP, unpublished report). Wind erosion is a threat to the sustainability of the land as well as the viability and quality of life for rural as well as urban communities.

Wind erosion in the United States is most widespread on agricultural land in the Great Plains states. Wind erosion is also a serious problem on cultivated organic soils, sandy coastal areas, alluvial soils along river bottoms, and other areas in the United States. In addition it is a major cause of soil degradation in arid and semiarid areas world wide. 

 LITERATURE CITED | DUST BOWL PHOTOGRAPHY |

The Wind Erosion Prediction System (WEPS)


Resources for WEPS:


USDA appointed a team of EWERU scientists to take a leading role in combining the latest in wind erosion science and technology with databases and computers.  The Wind Erosion Prediction System (WEPS) was designed to replace the Wind Erosion Equation (WEQ) model
.  It was developed by ARS and NRCS to serve as the wind erosion prediction software for conservation planning. 

Unlike WEQ, WEPS is a process-based, continuous, daily time-step model that simulates weather, field conditions, and erosion. It is a user friendly program that has the capability of simulating spatial and temporal variability of field conditions and soil loss/deposition within a field. WEPS can also simulate complex field shapes, barriers not on the field boundaries, and complex topographies. The saltation, creep, suspension, and PM10 components of eroding materials can also be reported separately by direction in WEPS. WEPS is designed to be used under a wide range of conditions in the U.S. and easily adapted to other parts of the world.

Soil erosion by wind is initiated when wind speed exceeds the saltation threshold velocity for a given field condition. After initiation, the duration and severity of an erosion event depends on the wind speed distribution and the evolution of the surface condition. Because WEPS is a continuous, daily, time-step model, it simulates not only the basic wind erosion processes, but also the processes that modify a soil's susceptibility to wind erosion. 

The structure of WEPS is modular and consists of a user-interface, a MAIN (supervisory) routine, seven submodels and four databases.

 

Most of the submodels within WEPS use daily weather (from the WEATHER submodel) as the natural driving force for the physical processes that change field conditions. The HYDROLOGY submodel accounts for changes in temperature and water status of the soil. Changes in the soil properties between management events are simulated in the SOIL submodel. The growth of crop plants is simulated in the CROP submodel, and their decomposition is accounted for in the DECOMPOSITION submodel. Step changes in the soil and biomass conditions generated from typical management practices such as tillage, planting, harvesting, and irrigation are modeled within the MANAGEMENT submodel of WEPS. Finally, the power of the wind on a subhourly basis is used to drive the EROSION submodel.

The Old Wind Erosion Equation (WEQ)


 

Introduction 

Although many of the principles of wind erosion were known before the 1930's, the foundations of modern wind erosion prediction technology largely began with the publication in 1941 of Ralph Bagnold's classic book titled "The Physics of Blown Sand and Desert Dunes". Further research was needed for application to agricultural fields, which are generally more complicated than sand dunes.  The complications include properties that change over time such as soil, aggregate size and stability, crusts, random and oriented roughness, field size, and vegetative cover.


 A history of the old WEQ prediction model was published in Aeolian Research

The Wind Erosion Equation (WEQ)
  
Using wind tunnels and field studies, the late Dr. William S. Chepil and co-workers set out in the mid-1950's to develop the first wind erosion prediction equation (WEQ) which was used by the Natural Resources Conservation Service (NRCS) and other action agencies throughout the country until recently.


WEQ has since been replaced by the more user friendly, processed based Wind Erosion Prediction System (WEPS).  WEPS represents a significant science improvement to predict wind erosion on site and quantify the offsite movement of soil to include PM-10 (particulate matter less than 10µm in size). 

Because field erodibility varies with field conditions, a procedure to solve WEQ for periods of less than one year was devised. In this procedure, a series of factor values are selected to describe successive management periods in which both management factors and vegetative covers are nearly constant.

 
Dr. Chepil and the Wind Erosion Tunnel located at
Kansas State University  - photo courtesy USDA-ARS-CGAHR

Erosive wind energy distribution is used to derive a weighted soil loss for each period. Soil loss for the management periods over a year are added to estimate annual erosion. Soil loss from the periods also can be added for a multi-year rotation, and the loss divided by the number of years to obtain an average, annual estimate.

WEQ was a widely used method (Excel Spreadsheet) for assessing average annual soil loss by wind from agricultural fields. The primary user of WEQ was the Natural Resources Conservation Service (NRCS). When WEQ was developed approximately 40 years ago, it was necessary to make it a simple mathematical expression, readily solvable with the computational tools available. However, WEQ had fundamental weaknesses because of its equation structures and its empirical representation of erosion processes. Since its inception, there have been a number of efforts to improve the accuracy, ease of application, and range of WEQ. Despite efforts to make such improvements, the structure of WEQ precluded adaptation to many problems. 

In 1986, the USDA began a more than 20-year effort to develop the next generation of wind erosion prediction technology.  The NRCS began using WEPS in its field offices in 2010. Find out more information on WEPS here.
   


Particulate Matter (PM-10)

Dust storm in Bird City, KS

“There are things floating around in the air.  Most of them, you cannot even see.  They are a kind of air pollution called particles or particulate matter.  In fact, particulate matter may be the air pollutant that most commonly affects people’s health.”

Quoted from the Pima County Dept. of Environmental Quality - Tucson, Arizona website.

"My anemometer is located only 9 feet off the ground and between windbreaks and registered in the 50-60 mph range but neighbors clocked 80-90 mph straightlined winds. It was an unbelievable storm. It reminded me of some hurricane videos I've seen. The roar grew until our house shook. The south side of the barn (far side in this view) was blown off its foundation."

 

Quote & Photo courtesy of John G. Courmerilh, Bird City (Cheyenne County), KS.  Taken Saturday, 29 May 2004.


Nature and Sources of the Pollutant:
Particulate matter less than 10µm in size (PM10) is a small fraction of the suspension sized material that may cause health problems when inhaled and other environmental problems.  Stringent Federal air quality standards regulate concentrations of PM10 as a health hazard.  Wind erosion has been linked to increased particulate matter emissions from agricultural fields as well as other sources such as sand dunes, unpaved roads, construction and mining sites, dry lake beds, rangelands, and forest lands.

Health and Environmental Effects: In 1987, EPA replaced the earlier Total Suspended Particulate (TSP) air quality standard with a PM-10 standard. The new standard focuses on smaller particles that are likely responsible for adverse health effects because of their ability to reach the lower regions of the respiratory tract. The PM-10 standard includes particles with a diameter of 10 micrometers or less (0.0004 inches or one-seventh the width of a human hair). EPA's health-based national air quality standard for PM-10 is 50 µg/m3 (measured as an annual mean) and 150 µg/m3 (measured as a daily concentration). Major concerns for human health from exposure to PM-10 include: effects on breathing and respiratory systems, damage to lung tissue, cancer, and premature death. The elderly, children, and people with chronic lung disease, influenza, or asthma, are especially sensitive to the effects of particulate matter. Acidic PM-10 can also damage human-made materials and is a major cause of reduced visibility in many parts of the U.S. New scientific studies suggest that fine particles (smaller than 2.5 micrometers in diameter) may cause serious adverse health effects. As a result, EPA is considering setting a new standard for PM-2.5. In addition, EPA is reviewing whether revisions to the current PM-10 standards are warranted.

For more information visit the US Environmental Protection Agency’s website:  http://www.epa.gov/airtrends/aqtrnd95/pm10.html

For information about the current air quality in your area visit:
http://airnow.gov/index.cfm?action=aqibasics.particle

 


Recent Wind Erosion Publications

CLICK HERE for a complete list of older publications in PDF form.


Recent Publications:

 

475

Chung, S.H., Herron-Thorpe, F.L., Lamb, B.K., VanReken, T.M., Vaughan, J.K., Gao, J., Wagner, L.E., and Fox, F.  2013.  Application of the wind erosion prediction system in the AIRPACT regional air quality modeling framework.  Transactions of the ASABE.  56(2):625-641.

474

Blanco-Canqui, H., Holman, J.D., Schlegel, A.J., and Tatarko, J.  2013.  Replacing fallow with cover crops in a semiarid soil: effects on soil properties.  Soil Science Society of America Journal.  77(3):1026-1034.  DOI: 10.2136/sssaj2013.01.0006.

473

Evers, B.J., Blanco-Canqui, H., Staggenborg, S.A., and Tatarko, J.  2013.  Dedicated bioenergy crop impacts on soil wind erodibility and organic carbon in Kansas.  Agronomy Journal.  105(5):1271-1276.

472

Gao, J., Wagner, L.E., Fox, F., Chung, S.H., Vaughan, J.K., and Lamb, B.K.  2013.  Spatial application of WEPS for estimating wind erosion in the pacific northwest.  Transactions of the ASABE.  56(2):613-624.

471

Wagner, L.E. and Fox, F.A.  2013.  The management submodel of the wind erosion prediction system.  Applied Engineering in Agriculture.  29(3):361-372.

469

Retta, A., Wagner, L.E., Tatarko, J., and Todd, T. 2013. Evaluation of bulk density and vegetation as affected by military vehicle traffic at Fort Riley, Kansas. Transactions of the ASABE. 56(2):653-665.

431

Kohake, D.J., Hagen, L.J., and Skidmore, E.L.  2010.  Wind Erodibility of Organic Soils.  Soil Science Society of America Journal.  74(1):250-257.

 

430

Mamedov, A.I., Wagner, L.E., Huang, C., Norton, L.D., and Levy, G.J.  2010.  Polyacrylamide effects on aggregate and structure stability of soils with differrent clay mineralogy Soil Science Society of American Journal.  74(5).

 

421

Hagen, L.J., van Pelt, S., and Sharratt, B.  2010.  Estimating the saltation and suspension components from field wind erosion.  Aeolian Research.  1:147-153.

 

404

Lagae, H.L., Langemeier, M., Lybecker, D., and Barbarick, K.  2009.  Economic value of biosolids in a semiarid agroecosystem Agronomy Journal.  101: 933-939.

 

Warrington, D.N., Mamedov, A.I., Bhardwaj, A.K., and Levy, G.L.  2009.  Primary particle size distribution of eroded material affected by degree of aggregate slaking and seal developmentEuropean Journal of Soil Science.  60:84-93.  Online doi:  10.1111/j.1365-2389.2008.01090.x.

 

De-Campos, A.B., Mamedov, A.I., and Huang, C.  2009.  Short-term reducing conditions decreases soil aggregation.  Soil Science Society of America Journal.  73:550-559.

 

419

Presley, D. and Tatarko, J.  2009.  Principles of wind erosion and its control.  Extension Publications.  MF-2860 September 2009.

Presley, D. and Tatarko, J.  2009. Principles of wind erosion and its control.  Extension Publications.  (Abstract)

Ihde, N., Presley, D., Tatarko, J., and Stone, L.  2009.  Wind erodibility, soil moisture, and freeze-thaw frequency: Implications of harvesting corn residue for energy feedstock in southwest Kansas(Abstract)

 

Tatarko, J., Stefonick, N.A. 2007. Wind Erodibility of Biosolids - Amended Soils: A Status Report. Proceedings of the Water Environment Federation. 12:893-904.  (Abstract)

Tatarko, J., Wagner, L.E.  2007.  An Introduction to the Wind Erosion Prediction System (WEPS).  Proceedings of the American Society of Agricultural and Biological Engineers 2007 Annual International Meeting; 17-20 June 2007; Minneapolis, MN.  2007 CD Rom. (Astract)

Lui, L.Y., E.L. Skidmore, E. Hasi, L. Wagner, and J. Tatarko. 2005. Dune sand transport as influenced by wind directions, speed and frequencies in the Ordos Plateau, China. Geomorphology.67:283-297 409

Van Donk, S.J., Wagner, L.E., Skidmore, E.L., Tatarko, J. 2005. Comparison of the Weibull Model with measured wind speed distributions for stochastic wind generation. Transactions of ASABE.  48 (2):503-510. 

 
 

Videos - Erosion Caused by Wind

Wid Erosion Control Video Cover

Produced by USDA-ARS-EWERU for NRCS, 2003. 35. min./Color.

A three-part educational video, which describe the physical basis for wind erosion processes and control systems. The video emphasize farming systems which target a goal of zero soil loss from wind erosion. It is intended to provide managers and other conservation partners with a better understanding of the physical principles of wind erosion and its control.

Soil Erosion by Wind and Its Control
Part I:
The Problem of Wind Erosion
Part II: Processes of Wind Erosion
Part III: Control of Wind Erosion

Available in VHS & DVD and with closed captioning.

Send requests for VHS or DVDs to:
Engineering & Wind Erosion Research Unit
1515 College Avenue
Manhattan, KS 66502
785-537-5542 or 785-776-2726
Requests can also be sent via email to: john.tatarko@ars.usda.gov

Dune sand in Wind Tunnel
This is an older video showing the saltation and creep movement of dune sand in the wind tunnel.

Close up of dune sand in Wind Tunnel
This is an older video showing a close up of sand movement in the wind tunnel.

Dune sand and Plants in Wind Tunnel
A video showing plant damage caused by the wind and sand particles in the wind stream. The first part of the video shows winter wheat in the wind tunnel while the second part shows young corn plants.
The Plow that Broke the Plains
Produced by Pare Lorentz, 1936. A U.S. Government Short Film about the Dust Bowl. 30. min.
Rain for the Earth, Part 1
Produced by The Works Projects Administration, 1937. A U.S. Government Film that includes Dust Bowl footage. ~10. min.

Last Modified: 6/6/2014