ARS | Publication request: WIND-INDUCED DUST GENERATION AND TRANSPORT MECHANICS ON A BARE AGRICULTURAL FIELD

Submitted to: Encyclopedia of Soils in the Environment
Publication Type: Book / Chapter
Publication Acceptance Date: July 2, 2004
Publication Date: December 1, 2004
Citation: Zobeck, T.M., Van Pelt, R.S. 2004. Erosion: Wind-induced. In: Hillel, D., editor. Encyclopedia of Soils in the Environment. Oxford, UK;Elsevier, Ltd. p. 470-478.

Interpretive Summary: Strong winds may cause wind erosion to blow dust when the ground is bare, dry, has loose erodible soil. Since this blowing dust may exceed dust air quality limits established by the United States Environmental Protection Agency, information on dust creation and movement in the atmosphere are needed to develop ways of reducing blowing dust. In this study we measured climatic properties and the airborne particles mass and concentration were made during three strong wind events on a bare, fine sandy loam field in west Texas. This study clearly shows that dust movement estimates were very sensitive to dust concentration measurement height. Measurements of the movement of fine particles of dust estimated between heights of 2m to 5m were 2 to 5 times those estimated between heights of 5m to 10m. The placement of sensors in relation to the edge of the eroding has a large effect on the results, depending on dust storm intensity. During the most intense storm event, the fine particle movement between heights of 2m to 5m measured at the sensor tower 200m from the unerodible edge of the field was almost 2.5 times as that measured at the tower 100m from the unerodible edge of the field. Vertical fine particle movement was closely related with horizontal sediment movement only when the winds came from the same direction during the entire duration of horizontal sediment movement measurements period.

Technical Abstract: Strong atmospheric winds may cause wind erosion and dust emissions on bare, dry, erodible fields. Since these dust emissions may exceed particulate matter limits established by the United States Environmental Protection Agency, information on dust generation and transport mechanics are needed to develop mitigation strategies. Measurements of climatic variables and airborne sediment mass and concentration were made during three strong wind events on a bare, fine sandy loam field in west Texas. This study clearly shows that dust flux estimate were very sensitive to dust concentration measurement height. PM10 flux values estimated between heights of 2m to 5m were 2 to 5 times those estimated between heights of 5m to 10m. Tower placement in relation to the upwind unerodible boundary produced significant differences in dust flux that varied with storm intensity. During the most intense storm event, the PM10 flux between heights of 2m to 5m measured at the tower 200m from the unerodible boundary was almost 2.5 times as that measured at the tower 100m from the unerodible boundary. Vertical PM10 dust flux was closely related with horizontal sediment flux only when the winds came from the same direction during the entire duration of horizontal sediment flux measurements.