|Zobeck, Teddy - Ted|
Submitted to: Earth Surface Processes and Landforms
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/9/2010
Publication Date: 10/1/2010
Citation: Panebianco, J.E., Buschiazzo, D.E., Zobeck, T.M. 2010. Comparison of different mass transport calculation methods for wind erosion quantification purposes. Earth Surface Processes and Landforms. 35(13):1548-1555. Interpretive Summary: Wind erosion is a significant environmental problem that affects millions of acres in the United States and around the world. Mathematical models are often used to estimate the dust transport. These models have been compared to samples of dust collected at various specific heights above the soil surface Many studies us only three sampling heights to estimate wind erosion while sampling more heights gives a better estimate. The objective of this study was to compare estimates of dust movement using only three sampling heights to comparisons made with nine sampling heights. Four different models to describe the samples collected at three to nine heights were tested using 147 erostion events on bare, smooth agricultural fields. The best model found to estimate dust movement with only three sampling height was an exponential equation. However, this estimate was about 40% lower then the best estimnate using nine heights. Application of a correction factor to account for this difference is recommended.
Technical Abstract: Quantitative estimation of the material transported by the wind is essential in the study and control of wind erosion, although methods for its calculation are still controversial. Sampling the dust cloud at discrete heights, fitting an equation to the data, and integrating this equation from the soil surface to a height is a widely accepted method. However, results obtained with sampling devices placed at different heights from the surface and using different mass flux profile models make comparisons between studies difficult, and also call into question the reliability of sediment transport estimations. The objective of this work was to evaluate the effect of using only three discrete sampling heights instead of sampling the full profile with six BSNE samplers plus a surface sampler, on the mass transport calculations. This was accomplished using four simple approaches: two different widely used equations, a two-parameter Gaussian model, and linear spline interpolation. Wind erosion was measured on an Entic Haplustoll during 147 events in a bare, smooth, 1 ha agricultural field surrounded by a non erodible boundary. Wind eroded sediment mass flux was calculated using fitting software. A rational equation was found to be mathematically limited for the estimation of wind eroded sediment mass flux under certain circumstances, and a Gaussian model was found to be inadequate for describing the vertical mass flux profile data under the conditions of this study. A simple exponential model, proposed by numerous authors, proved to be robust and simple to apply, fitting the field data reasonably well for all the events. Using data from three discrete sampling heights instead of nine generally resulted in lowered mass transport values. Linear interpolation generally resulted in higher mass transport estimates.