Meltwater‐Driven Water‐Level Fluctuations of Bosten Lake in Arid China Over the Past 2,000 Years

• Published in: Geophysical research letters 2021-01, Vol.48 (2), p.n/a
• Main Authors: Li, Yuan, Hu, Ling, Zhao, Yongtao, Wang, Haipeng, Huang, Xiaozhong, Chen, Guangjie, Leppänen, Jaakko Johannes, Fontana, Luciane, Ren, Lele, Shi, Zhilin, Liu, Bing, Zhao, Hui
• Format: Article
• Language: English
• Subjects: Bosten Lake; Cladocera; Silk Road; water resources
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2020GL090988

Changes in water storage of the large freshwater lakes in Arid Central Asia (ACA) have significant implications for the regional social and ecological systems. Here we present a lake‐level record of the past 2,000 years from Bosten Lake, a large freshwater body in the region, using the sedimentary Cladoceran microfossil. The results suggest that a lower lake level and a higher salinity occurred during the cold, high‐precipitation periods of 280–450 AD and 1570–1850 AD, and that a higher lake level and a lower salinity occurred during the warm, low‐precipitation period of 450–1570 AD. The findings show that on the centennial timescale, the water‐level fluctuations of Bosten Lake were modulated mainly by temperature‐driven meltwater input. In addition, the shortage of freshwater during the cold period may have contributed to the collapse of the ancient cities and the depression of the trade along the Silk Road. Plain Language Summary Bosten Lake, the largest inland freshwater lake of China, is located in the northeast part of Tarim Basin. The lake is important freshwater resources and plays an important role in sustaining regional social and ecological systems. In this study, we reconstructed the water‐level fluctuations of the lake over the past 2,000 years, based mainly on the Cladoceran microfossil analyses of a sediment core. The results suggest that a lower lake level occurred during the cold, high‐precipitation periods of 280–450 AD and 1570–1850 AD, and that a higher lake level occurred during the warm, low‐precipitation period of 450–1570 AD. The findings show that on the centennial timescale, the water‐level fluctuations of Bosten Lake were modulated mainly by temperature‐driven meltwater input. In addition, historical documents reveal that a large number of ancient cities in the Tarim Basin were abandoned in the third‐sixth centuries and that the trade along the ancient Silk Road was relatively depressed during that time, coinciding with the salinization and the shrinking of Bosten Lake. This suggests that the shortage of freshwater during this cold period may have contributed to the collapse of the ancient cities and the depression of the trade along the Silk Road. Key Points On the centennial timescale, the water‐level fluctuations of Bosten Lake were modulated mainly by temperature‐driven meltwater input The shortage of freshwater during the cold period may have contributed to the collapse of the ancient cities along the Silk Road