The characteristics of aeolian sediment flux profiles in the south-eastern Tengger Desert



Deserts are one of the most important dust sources in the world. Because dust content changes as a function of height at low levels in the atmosphere, this affects long-term dust transport. In this paper, field data measured above shifting sands in the south-eastern Tengger Desert were used to analyse the vertical distribution of sediment fluxes in the near-surface layer (0 to 48 m). It was possible to express horizontal sediment flux as a power function, but aeolian deposition as a function of height could be expressed as an exponential function. There are two curve types for the particle size distributions in the horizontal sediment flux and aeolian deposition: bimodal and unimodal curves. For the horizontal sediment flux and aeolian deposition, heights of 24 m and 32 m, respectively, were the key heights in the size distribution curve; below these heights, the curve was bimodal, whereas above these heights, it was unimodal. At heights of 4 to 16 m, and especially between 8 m and 12 m, the data were particularly interesting because the sediment size, transport mode, degree of sorting, and the skewness and kurtosis change. For the horizontal sediment flux, wind turbulence moved saltating particles higher than expected.