Aeolian salinization of soils on the piedmont plain of Eastern Tian Shan (Lake Ebinur area, China)

摘要

This study is focused on the effect of aeolian transport on soil formation and salinization in the piedmont plain of the northern slope of Tian Shan (Xinjiang-Uygur Autonomous Region of China). On the basis of the data on aeolian input of dust and salts (determined by dust collectors) and soil salinity at the 300-km transect it is shown that soil formation and salinization is closely related to aeolian processes. The main source of aeolian material is the dried up bottom of Lake Ebinur (wet playa). Maximum soil salinity (3-6% of salts) is observed in the soils near Jinghe settlement where the maximum aeolian input of salts is also registered. In the soils beyond 100 km from the dried bottom of the lake, salt content is low (0.1-0.4%). Chemical composition of salts in the soils is related to chemical composition of aeolian material. Chloride salts prevail in the soils located in the areas with the high Cl~- to SO_4~(2-) ratios (from 0.8 to 1.5) in aeolian salts. In places with a predominance of sulphates in the composition of aeolian salts, soils are characterized by the sulphate type of salinization. Prehminary calculations show that the formation of the modern profile of the studied soils takes about 2000 years.