新疆艾比湖地区盐尘的沉积通量及其物质组成

以新疆准噶尔盆地西部的艾比湖地区为研究区,通过野外降尘监测、采样分析等方法,研究了艾比湖地区含盐粉尘的沉积通量和物质组成特征.结果表明:艾比湖干涸湖底是盐尘的输出源,盐尘的化学组成主要是无水芒硝、白钠镁矾、氯化钠等盐碱粉尘及Cr、Pb、Mn、Cu、Ni等潜在毒性元素.艾比湖地区盐尘的沉积通量约为79~381 g·m-2·a-1,盐的沉积通量约为4~61 g·m-2·a-1.盐尘的粒径分布以2~63μm的粉砂粒级为主,大于63μm的砂粒级所占比例很小.特殊的地形条件、大风天气、稀疏的植被覆盖、疏松的大面积尘源是艾比湖湖底风蚀和盐尘输送的有利条件.

Sediment fluxes and material composition of the salt dust in Ebinur Lake region,Xinjiang

In many arid and semiarid lands, dry lake beds (saline playa) are tremendous sources of unconsolidated salt-rich sediments in favor of aeolian material transport. Severe salt-dust storms caused by the erosion of such landforms have become very harmful natural phenomena. Taking the playa of Ebinur Lake, a large mineral aerosol source in the western Junggar Basin in Xinjiang, China, as the study site, through field investigation and sample analysis, the sediment fluxes, material composition and particle size distribution of the saline dust are studied in this paper. The sediment fluxes of atmospheric dust fall (containing salt) range from about 79 to 381 g·m^-2·a^-1 in Ebinur Lake region. The salinity of the dust ranges from 43 to 185 g·kg^-1 and the sediment fluxes of salts range from 4 to 61 g·m^-2·a^-1. The dust is a chemical dust, which consists of dense fine sulfates, chlorides and potentially toxic elements, and causes serious air pollution, resulting in soil salinization and vegetation degradation.