关键词: 大气降尘, 塔克拉玛干沙漠腹地, 粒级, 厚度, 土壤水分蒸发, 盐分运移, 土体大孔隙, 半径范围和数量, 平均体积, 水分穿透曲线, Poiseulle方程

Abstract: By using mcirolysimeter, a laboratory simulation experiment was conducted to study the effects of the  grain size and thickness of dust deposits on the soil water evaporation and salt movement in the hinterland of the Taklimakan Desert. Under the same initial soil water content and deposition thickness condition, finer-textured (<0063 mm) deposits promoted soil water evaporation, deeper soil desiccation, and surface soil salt accumulation, while coarse-textured (0063〖KG-*2〗-〖KG-*7〗2 mm) deposits inhibited soil water evaporation and decreased deeper soil water loss and surface soil salt accumulation. The inhibition effect of  the grain size of dust deposits on soil water evaporation had an inflection point at the grain size 020 mm, i.e., increased with increasing grain size when the grain size was 0063〖KG-*2〗-〖KG-*7〗020 mm but decreased with increasing grain size when the grain size was > 020 mm. With the increasing thickness of dust deposits, its inhibition effect on soil water evaporation increased, and there existed a logarithmic relationship between the dust deposits thickness and water evaporation. Surface soil salt accumulation had a negative correlation with dust deposits thickness. In sum, the dust deposits in study area could affect the stability of arid desert ecosystem.

Key words: dust deposits, Central of Taklimakan Desert, grain size, thickness, soil water evaporation, salt movement, soil macropore, radius range and amount, average volume, water breakthrough curve, Poiseuille equation.