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Titel |
Characterizing contributions of glacier melt and groundwater during the dry season in a poorly gauged catchment of the Cordillera Blanca (Peru) |
VerfasserIn |
M. Baraer, J. M. McKenzie, B. G. Mark, J. Bury, S. Knox |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7340
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Digitales Dokument |
URL |
Erschienen |
In: 4th EGU Alexander von Humboldt Conference "The Andes: Challenge for Geosciences" ; Nr. 22 (2009-10-13), S.41-49 |
Datensatznummer |
250014727
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Publikation (Nr.) |
copernicus.org/adgeo-22-41-2009.pdf |
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Zusammenfassung |
The retreat of glaciers in the tropics will have a significant impact on
water resources. In order to overcome limitations with discontinuous to
nonexistent hydrologic measurements in remote mountain watersheds, a
hydrochemical and isotopic mass balance model is used to identify and
characterize dry season water origins at the glacier fed Querococha basin
located in southern Cordillera Blanca, Peru. Dry season water samples,
collected intermittently between 1998 and 2007, were analyzed for major ions
and the stable isotopes of water (δ18O and δ2H).
The hydrochemical and isotopic data are analysed using conservative
characteristics of selected tracers and relative contributions are
calculated based on pre-identified contributing sources at mixing points
sampled across the basin. The results show that during the dry-season,
groundwater is the largest contributor to basin outflow and that the flux of
groundwater is temporally variable. The groundwater contribution
significantly correlates (P-value=0.004 to 0.044) to the antecedent
precipitation regime at 3 and 18–36 months. Assuming this indicates a
maximum of 4 years of precipitation accumulation in groundwater reserves,
the Querococha watershed outflows are potentially vulnerable to multi-year
droughts and climate related changes in the precipitation regime. The
results show that the use of hydrochemical and isotopic data can contribute
to hydrologic studies in remote, data poor regions, and that groundwater
contribution to tropical proglacial hydrologic systems is a critical
component of dry season discharge. |
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