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Glacier meltwater runoff process analysis using δD and δ18O isotope and chemistry at the remote Laohugou glacier basin in western Qilian Mountains, China
*Corresponding author: Dong Zhiwen, Research Assistant, E-mail: dongzhiwen@lzb.ac.cn
Author: Wang Caixia (1987-), Master Student, specialized in environmental change in arid regions.E-mail: happyabear@163.com
Received date: 2015-07-24
Accepted date: 2015-10-29
Online published: 2016-06-15
Supported by
National Natural Science Foundation of China, No.41301065
The West Light Program for Talent Cultivation of Chinese Academy of Sciences
Copyright
Stable hydrogen and oxygen isotope has important implication on water and moisture transportation tracing research. Based on stable hydrogen (δD) and oxygen (δ18O) isotope using a Picarro L1102-i and water chemistry (e.g. major ions, pH, EC and TDS) measurement, this study discussed the temporal variation and characteristics of stable hydrogen and oxygen isotope, chemistry (e.g. TDS, pH, EC, Ca2+, Mg2+, Na+ and Cl-) in various water bodies including glacier meltwater runoff, ice and snow, and precipitation at the Laohugou glacier basin during June 2012 to September 2013. Results showed that δD and δ18O in the meltwater runoff varied obviously with the temporal change from June to September, showing firstly increasing trend and then decreasing trend, with the highest values in July with high air temperature and strong glacier melting, which could indicate the temporal change of glacier melting process and extent. Variations of δD and δ18O in the runoff were similar with that of snow and ice on the glacier, and the values were also above the GMWL, which probably implied that the glacier runoff was mainly originated from glacier melting and precipitation supply. The glacier meltwater chemical type at the Laohugou glacier basin were mainly composed by Ca-Na-HCO3-SO4 and Ca-Mg-HCO3-SO4, which also varied evidently with the glacier melting process in summer. By analyzing the temporal change of stable hydrogen and oxygen isotope and chemistry in the melting period, we find it is easy to separate the components of the snow and ice, atmospheric precipitation and melt-runoff in the river, which could reflect the change process of glacier melting during the melting period, and thus this work can contribute to the glacier runoff change study of large-scale region by stable isotope and geochemical method in future.
WANG Caixia , DONG Zhiwen , QIN Xiang , ZHANG Jie , DU Wentao , WU Jinkui . Glacier meltwater runoff process analysis using δD and δ18O isotope and chemistry at the remote Laohugou glacier basin in western Qilian Mountains, China[J]. Journal of Geographical Sciences, 2016 , 26(6) : 722 -734 . DOI: 10.1007/s11442-016-1295-y
Figure 1 Map showing the location of sampling sites in the Laohugou glacier basin (a), and the sites of snowpits (A), glacier ice (B), runoff at the terminus (C) and runoff 500 m away from the terminus (D) are shown on (b) |
Table 1 Comparison of chemistry of hydrogen and oxygen isotope ratio in the snow and ice, precipitation and runoff in the Laohugou glacier basin |
Sample sites | Elevation (m) | SO42- (μg L-1) | Mg2+ (μg L-1) | Ca2+ (μg L-1) | HCO3- (μg L-1) | Na+ (μg L-1) | EC (μs cm-1) | pH | TDS (mg L-1) | δ18O (‰) | δD (‰) | Chemical type |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Snow and ice | 4500 -5010 | 2086.6 | 115.3 | 2580 | 2245.6 | 1044.1 | 12.2 | 5.6 | 21.3 | -15.62 | -93.7 | Ca-Na- HCO3-SO4 |
Terminus meltwater | 4260 | 5023 | 2819.1 | 7313 | 4703 | 6910 | 135 | 7.39 | 61.4 | -12.7 | -87.61 | Ca-Na- HCO3-SO4 |
500 m down terminus | 4200 | 12018 | 2832 | 6243.2 | 5011.5 | 1326 | 186.5 | 7.21 | 124.3 | -13.5 | -83.9 | Ca-Mg- HCO3-SO4 |
Figure 2 Correlation analysis of hydrogen and oxygen isotope in the Laohugou basin, among which GMWL is δD=8δ18O+10‰ |
Figure 3 Averaged Outgoing Long Wave radiation (ORL) and winds distribution in the Laohugou and surrounding regions. (a) summer ORL; (b) winter and spring ORL; (c) wind distribution in summer 2000-2014; (d) wind distribution in winter and spring of 2000-2014 |
Figure 4 Air temperature and precipitation change in the year 2010-2011 at 4200 m sites in the Laohugou basin |
Figure 5 Chemical compositions in the various kinds of water at the Laohugou glacier basin |
Figure 6 Stable hydrogen and oxygen isotope and TDS correlation analysis in various water sampling sites of the Laohugou basin |
Figure 7 Stable hydrogen and oxygen isotope variation with glacier melting in the summer 2012-2013 |
Figure 8 Temporal variation of the correlation between stable oxygen isotope and Cl- in the runoff of the Laohugou Glacier No.12 |
Figure 9 pH and EC variations in the glacier meltwater of the Laohugou glacier basin in summer 2012 |
Table 2 Chemistry variation with month change in the glacier meltwater runoff in 2013 |
Sample | Time | Sample number (n) | SO42- (μg L-1) | Mg2+ (μg L-1) | Ca2+ (μg L-1) | Cl- (μg L-1) | Na (μg L-1) | EC (μs cm-1) | pH | TDS (mg L-1) |
---|---|---|---|---|---|---|---|---|---|---|
Melt runoff | June | 11 | 2015.3 | 982 | 3214 | 291 | 1215 | 79 | 7.21 | 32.1 |
July | 23 | 5579 | 2321 | 4329 | 113 | 2145 | 146 | 7.32 | 86.2 | |
August | 28 | 3298.6 | 3176 | 3876 | 342 | 1137 | 133 | 7.43 | 65.4 | |
September | 12 | 1126.8 | 874 | 2569 | 98 | 673 | 65 | 7.10 | 43.9 |
The authors have declared that no competing interests exist.
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