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• 收稿日期:2014-08-29 接受日期:2014-09-22 出版日期:2015-02-15 发布日期:2015-02-15

### Hydrological processes of glacier and snow melting and runoff in the Urumqi River source region, eastern Tianshan Mountains, China

Meiping SUN1(), Xiaojun YAO1, Zhongqin LI2, Mingjun ZHANG1

1. 1. College of Geography and Environment Science, Northwest Normal University, Lanzhou 730070, China
2. State Key Laboratory of Cryosphere Sciences, Cold and Arid Region Environment and Engineering Research Institute, CAS, Lanzhou 730000, China
• Received:2014-08-29 Accepted:2014-09-22 Online:2015-02-15 Published:2015-02-15
• About author:

Author: Sun Meiping (1981-), PhD and Associate Professor, specialized in the research of hydrological processes and the climate change impact assessment. E-mail:sunmeiping1982@163.com

• Supported by:
National Science and Technology Support Plan Projects, No.2012BAC19B07;Scientific Research Project of Higher Learning Institution in Gansu Province, No.2013A-018;Project of Scientific Ability Promoting of Young Teachers of Northwest Normal University, No.NWNU- LKQN-12-20

Abstract:

Hydrological processes were compared, with and without the influence of precipitation on discharge, to identify the differences between glacierized and non-glacierized catchments in the Urumqi River source region, on the northern slope of the eastern Tianshan Mountains, during the melting season (May-September) in 2011. The study was based on hydrological data observed at 10-min intervals, meteorological data observed at 15-min intervals, and glacier melting and snow observations from the Empty Cirque, Zongkong, and Urumqi Glacier No.1 gauging stations. The results indicated that the discharge differed markedly among the three gauging stations. The daily discharge was more than the nightly discharge at the Glacier No.1 gauging station, which contrasted with the patterns observed at the Zongkong and Empty Cirque gauging stations. There was a clear daily variation in the discharge at the three gauging stations, with differences in the magnitude and duration of the peak discharge. When precipitation was not considered, the time-lags between the maximum discharge and the highest temperature were 1-3 h, 10-16 h, and 5-11 h at the Glacier No.1, Empty Cirque, and Zongkong gauging stations, respectively. When precipitation was taken into consideration, the corresponding time-lags were 0-1 h, 13 h, and 6-7 h, respectively. Therefore, the duration from the generation of discharge to confluence was the shortest in the glacierized catchment and the longest in the catchment where was mainly covered by snow. It was also shown that the hydrological process from the generation of discharge to confluence shortened when precipitation was considered. The factors influencing changes in the discharge among the three gauging stations were different. For Glacier No.1 station, the discharge was mainly controlled by heat conditions in the glacierized region, and the discharge displayed an accelerated growth when the temperature exceeded 5°C in the melt season. It was found that the englacial and subglacial drainage channel of Glacier No.1 had become simpler during the past 20 years. Its weaker retardance and storage of glacier melting water resulted in rapid discharge confluence. It was also shown that the discharge curve and the time-lag between the maximum discharge and the highest temperature could be used to reveal the evolution of the drainage system and the process of glacier and snow melting at different levels of glacier coverage.