Streamwater hydrograph separation in an alpine glacier area in the Qilian Mountains,northwestern China |
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| Authors: | Wu Jin-Kui Wu Xiu-Ping Hou Dian-Jiong Liu Shi-Wei Zhang Xue-Yan Qin Xiang |
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| Institution: | 1. Laboratory of Watershed Hydrology and Ecology, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, China;2. Qilianshan Station of Glaciology and Ecologic Environment, State Key Laboratory of Cryospheric Science, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, China;3. Institute for Landscape Ecology and Resources Management, Justus-Liebig-University Giessen, Giessen, Germanyjkwu@lzb.ac.cn;5. The Lanzhou Branch of the Natural Science Library, Chinese Academy of Sciences, Lanzhou, China;6. Qilianshan Station of Glaciology and Ecologic Environment, State Key Laboratory of Cryospheric Science, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, China |
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| Abstract: | ABSTRACTGlacier-melt-induced changes in runoff are of concern in northwestern China where glacier runoff is a major source for irrigation, industries and ecosystems. Samples were collected in different water mediums such as precipitation, glacial ice/snowcover, meltwater, groundwater and streamwater for the analysis of stable isotopes and solute contents during the 2009 runoff season in the Laohugou Glacial Catchment. The multi-compare results of δ18O values showed that significant difference existed in different water mediums. Source waters of streamflow were determined using data of isotopic and geochemical tracers and a three-component hydrograph separation model. The results indicated that meltwater dominated (69.9 ± 2.7%) streamflow at the catchment. Precipitation and groundwater contributed 17.3 ± 2.3% and 12.8 ± 2.4% of the total discharge, respectively. According to the monthly hydrograph, the contribution of snow and glacier meltwater varied from 57.4% (September) to 79.1% (May), and that of precipitation varied from 0% (May) to 34.6% (September). At the same time, the monthly contribution of groundwater kept relatively steady, varying from 9.7% (June) to 20.9% (May) in the runoff season. Uncertainties for this separation were mainly caused by the variation of tracer concentrations. It is suggested that the end-member mixing analysis (EMMA) method can be used in the runoff separation in an alpine glacial catchment. Editor Z.W. Kundzewicz; Associate editor Not assigned |
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| Keywords: | glacial catchment end-member mixing analysis stable isotopes meltwater |
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