Stream temperature dynamics in Nam Co basin, southern Tibetan Plateau Stream temperature dynamics in Nam Co basin, southern Tibetan Plateau

最小化 最大化

Vol14 No.12: 2458-2470

Title】Stream temperature dynamics in Nam Co basin, southern Tibetan Plateau

Author】GAO Tan-guang1*; KANG Shi-chang2,3; ZHANG Ting-jun1; YANG Da-qing4; SHANG Jian-guo1; QIN Xiang2

Addresses】1 College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; 2 State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 3 CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China; 4 National Hydrology Research Centre, Environment Canada, Saskatoon, Saskatchewan, S7N 3H5, Canada

Corresponding authorgaotanguang@163.com

Citation】Gao TG, Kang SC, Zhang TJ, et al. (2017) Stream temperature dynamics in Nam Co basin, southern Tibetan Plateau. Journal of Mountain Science 14(12). https://doi.org/10.1007/s11629-016-4234-6

DOI】https://doi.org/10.1007/s11629-016-4234-6

Abstract】Stream temperatures are sensitive to climate change and runoff regime variations. A comprehensive understanding on the effects of glacial melting on the stream temperatures are important in the Tibetan Plateau, of which contains the largest ice volume outside Polar Regions. This study documented the high-resolution stream temperature thermal regimes from glacier-fed and non-glacial rivers at four sites, versus a high-resolution glacier mass balance monitoring at Zhadang glacier, during summer melt seasons from 2007‒2009 in the Nam Co basin of southern Tibetan Plateau. The results showed mean summer stream temperature and magnitude of daily thermal variation were lower at all sites when compared with alpine glacierized environments at lower latitudes. Mean stream temperatures for glacier-fed rivers (4.0°C to 6.5°C) were minimum and least variable near the glacier terminus with increasing toward downstream (+0.13°Ckm–1 to +0.28°C km–1). Meanwhile, stream temperature in 2008 was similar to that in 2007 and 2009. For the non-glacial rivers, mean stream temperatures was about 9.0°C with significantly warmer in summer months in 2009 and 2007 than that in 2008. These differences indicated that stream temperature was strongly influenced by discharge and precipitation. Particularly, the glacier mass balance played a large role on the stream temperature directly when the glacier melt contributed more than 50% of the glacial river runoff. Our results demonstrated the stream thermal variability from southern Tibetan rivers and provided new insight into the influence of glacier mass balance on stream thermal variability in high-altitude river system.

Keywords】Stream temperature; Thermal regime; Glacier mass balance; Tibetan Plateau