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| Titel |
Stable water isotope variation in a Central Andean watershed dominated by glacier and snowmelt |
| VerfasserIn |
N. Ohlanders, M. Rodriguez, J. McPhee |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 3 ; Nr. 17, no. 3 (2013-03-07), S.1035-1050 |
| Datensatznummer |
250018821
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| Publikation (Nr.) |
 copernicus.org/hess-17-1035-2013.pdf |
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| Zusammenfassung |
| Central Chile is an economically important region for which water supply is
dependent on snow- and ice melt. Nevertheless, the relative contribution of
water supplied by each of those two sources remains largely unknown. This
study represents the first attempt to estimate the region's water balance
using stable isotopes of water in streamflow and its sources. Isotopic ratios
of both H and O were monitored during one year in a high-altitude basin with
a moderate glacier cover (11.5%). We found that the steep altitude
gradient of the studied catchment caused a corresponding gradient in snowpack
isotopic composition and that this spatial variation had a profound effect on
the temporal evolution of streamflow isotopic composition during snowmelt.
Glacier melt and snowmelt contributions to streamflow in the studied basin were
determined using a quantitative analysis of the isotopic composition of
streamflow and its sources, resulting in a glacier melt contribution of
50–90% for the unusually dry melt year of 2011/2012. This suggests that
in (La Niña) years with little precipitation, glacier melt is an
important water source for central Chile. Predicted decreases in glacier melt
due to global warming may therefore have a negative long-term impact on water
availability in the Central Andes. The pronounced seasonal pattern in
streamflow isotope composition and its close relation to the variability in
snow cover and discharge presents a potentially powerful tool to relate
discharge variability in mountainous, melt-dominated catchments with related
factors such as contributions of sources to streamflow and snowmelt transit
times. |
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