Deposition Rate and Chemical Composition of the Aeolian Dust from a Bare Saline Playa, Ebinur Lake, Xinjiang, China

An ongoing project monitors saline dust transportation and accumulation in the Western Junggar Basin to determine the rate and chemical composition of dust inputs to soils and their impact on snow/ice melt and vegetation degradation of the surrounding areas. The 1-year record from ten dust trap sites in the Ebinur region of northwest China reveals that yearly deposition rates fluctuate strongly between different sampling sites. The mass accumulation rates (fluxes) of the dust, including water-soluble solutes and trace element, range from 79 to 381 g m(-2) year(-1). With increasing distance from the dry lake bed, dust deposition gradually decreases. The salinity of the dust ranges from about 43 to 185 g kg(-1) and the mass-soluble salt fluxes range from 4 to 61 g m(-2) year(-1). The types of water-soluble salt are different at different sampling sites. In all samples, the major types of water-soluble salts in the dust are sulfates and chlorides. Sulfate and chloride are the major anions while sodium and calcium are the main cations, and nitrate was not found in any dust samples. Potentially toxic trace elements such as Cd, Cr, Pb, Mn, As, Cu, and Ni are present in all samples, with high levels of Cr, Pb, Mn, Cu, and Ni. The dust is a chemical dust in that it consists of dense fine sulfates, chlorides and potentially toxic elements, and causes serious air pollution, resulting in soil salinization and vegetation degradation and accelerating snow/ice melt.