Bulk transportation of sand particles in quantitative simulations of dune field evolution

Bulk transportation of sand particles is a key process controlling and quantifying the evolution of aeolian dune field. Sand amount eroded by wind within a given period is usually depicted in terms of ‘sand body elements’, whose thickness and transportation distance have direct impact on the accuracy of simulated spatiotemporal scales and the efficiency of quantitative simulations. This paper presents a detailed analysis to the rule of determining the thickness and transportation distance of ‘sand body elements’, which can be described in analytical formulas with respect to sand diameter, frictional wind velocity, and time interval of computational simulations. Following this model, the efficiency of quantitative simulations of dune field evolution is greatly enhanced without losing accuracy.

Graphical abstractSummary: The variations of coefficients knn, lnn, knl and lno with respect to local frictional wind velocity (u*)n and sand diameter Ds. That is, with local frictional wind velocity (u*)n increasing, coefficients knn and knl increase but lnn decreases. With sand diameter Ds increasing, knn, knl and lno decrease but lnn increases.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► This paper presents analytical formulas describing the thickness and transportation distance of ‘sand body elements’. ► The formulas reveal the main changing laws of the thickness and transportation distance of ‘sand body elements’. ► The formulas reduce 60% of the simulation time required for reproducing the evolution process of a dune field.