Aeolian sediment fingerprinting in the Cuona Lake Section along the Qinghai-Tibetan Railway

Abstract

Quantitative analyses of aeolian sediment provenance are necessary to elucidate aeolian sand pathways and define objective targets for control measures. In the present study, annual wind data and remote sensing information were utilized to ascertain the source of aeolian sediments along the Cuona Lake Section of the Qinghai-Tibetan Railway (QTR). Fingerprinting approach with different tracer selection strategies was used to assess contributions of each source types. The results indicated that (1) wind erosion behaviours that contribute to sand sediment occur mainly on the west side of sandy areas during October to April. The resultant drift potential of this period reached 1086.18 VU, indicating a high energy level. (2) The aeolian desertified land within the source area expanded by 8.05 km2 from 2001 to 2017. The degraded alpine meadow, bare hilly land and river courses were identified as potential sources of aeolian sediments. (3) The contributions from degraded alpine meadow, bare hilly land and river courses were estimated as 4%, 58% and 38%, respectively. Synthesising these results, appropriate control measures for the bare hilly land and river courses on the west side of Cuona Lake should be able to greatly restrict sand transport and alleviate the railway sand hazard. This study will provide a firm basis for sand hazard control in the Cuona Lake section and can be utilized as references for other regions encountering threats from aeolian sand.