Physical and chemical characteristics of an eroded dry lake bed in the Mu Us Desert
Jie Lei, Guo-ming Zhang, Lian-you Liu, Zhi-qiang Qu, Hai-ming Wen, Yan-yan Yang, Jia-dong Dai
Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing, China
Dried lakes or playas form unconsolidated salt-rich sediments which are easily eroded by strong winds. The produce saline-alkaline dust storms which influence ecosystems and human health in the downwind regions. In this paper, we use Bu-zai-nur as a study area on Mu Us Desert. The aim is to improve the management of saline-alkaline dust storms and improve the recovery of the dry lake bed ecosystem. We analysed the dynamics of the soil physical and chemical characteristics from the lake center to the lakeside in the downwind direction. Our results indicated that from the centre of the lake the particle size of Bu-zai-nur mainly is fine and coarse sand, which increases with distance. Fine and coarse sand are diminished gradually, and the very fine sand, silt and clay content increase gradually, medium sand concentration has no obvious change. The soil moisture content and soil bulk density showed a trend of increasing with distance. The soil pH, soluble and conductivity decrease gradually. Except for sand dunes and fixed sandy land are given priority to with Ca2+, the rest of the samples mainly are Na+ for the Cationic; and the anion primary is Cl-, followed by SO42-, HCO3-, the ion content of sand dunes and fixed sandy land are lower than the rest of the sample. Overall, the study area's soil has relatively serious alkalization , and it shows obvious regular changes of the soil's physical and chemical characteristics on the downwind areas, parts of this area exists certain differences because of the different surface features. Since sand dune area, the farther away from the central of the lake the more obvious wind erosion traces, probably because it's the source area of the saline-alkaline dust storms.