Vol16 No.9: 1987-2000
【Title】Spatial distribution and formation mechanism of aeolian sand in the middle reaches of the Yarlung Zangbo River
【Author】LIU Yong, WANG Yun-sheng, SHEN Tong
【Addresses】1 State Key Lab. of Geo-Hazard Prevention and Geo-Environment Protection, Chengdu University of Technology, Chengdu 610059, China; 2 Institute of Exploration Technology, Chinese Academy of Geological Sciences, Chengdu 710043, China
【Corresponding author】LIU Yong
【Citation】Liu Y, Wang YS, Shen T (2019) Spatial distribution and formation mechanism of aeolian sand in the middle reaches of the Yarlung Zangbo River. Journal of Mountain Science 16(9). https://doi.org/10.1007/s11629-019-5509-5
【Abstract】Aeolian sand landforms in the Yarlung Zangbo River (YZR) valley are a special type of aeolian landform that has attracted the attention of many scholars. However, the spatial distribution as well as the formation mechanism of aeolian sand has rarely been reported with integrated studies. In this paper, for remote sensing interpretation, scanning electron microscopy (SEM), X-ray diffraction (XRD) and particle size distribution (PSD) methods were used to analyze the spatial distribution and the deposition characteristics of aeolian sand. Combined with wind data and topography, the main driving factors and the formation mechanism of aeolian sand landforms were also examined. In the middle reaches of the YZR valley, there is a total of 2324.43 km2 of aeolian sand, especially on the north bank of the wide valleys. In different wide valleys, the aeolian sand landforms exhibit a decreasing trend from the upstream to the downstream regions in both the area and expansion rate of aeolian sand. The cyclonic vortexes generated by the westerly winds and glacial winds are the main driving factors for transporting alluvial sand to the riverbank areas to form aeolian dunes. There are three main types of sand dunes in the river valley: climbing dunes, lee dunes and circumfluent dunes. Climbing dunes and lee dunes are mostly located west of the Jiacha Gorge, and the circumfluent dunes are mostly located east of the Jiacha Gorge.
【Keywords】Aeolian processes;Remote sensing interpretation; Scanning electron microscopy; X-ray diffraction; Particle size distribution; Glacial winds; Cyclonic vortexes.