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Titel |
Tracer-based analysis of spatial and temporal variations of water sources in a glacierized catchment |
VerfasserIn |
D. Penna, M. Engel, L. Mao, A. Dell'Agnese, G. Bertoldi, F. Comiti |
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 ; 18, no. 12 ; Nr. 18, no. 12 (2014-12-17), S.5271-5288 |
Datensatznummer |
250120569
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Publikation (Nr.) |
copernicus.org/hess-18-5271-2014.pdf |
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Zusammenfassung |
Snow-dominated and glacierized catchments are important sources of fresh
water for biological communities and for populations living in mountain
valleys. Gaining a better understanding of the runoff origin and of the
hydrological interactions between meltwater, streamflow and groundwater is
critical for natural risk assessment and mitigation as well as for effective
water resource management in mountain regions. This study is based on the
use of stable isotopes of water and electrical conductivity as tracers to
identify the water sources for runoff and groundwater and their seasonal
variability in a glacierized catchment in the Italian Alps. Samples were
collected from rainfall, snow, snowmelt, ice melt, spring and stream water
(from the main stream at different locations and from selected tributaries)
in 2011, 2012 and 2013. The tracer-based mixing analysis revealed that,
overall, snowmelt and glacier melt were the most important end-members for
stream runoff during late spring, summer and early fall. The temporal
variability of the tracer concentration suggested that stream water was
dominated by snowmelt at the beginning of the melting season (May–June), by
a mixture of snowmelt and glacier melt during mid-summer (July–early
August), and by glacier melt during the end of the summer (end of
August–September). The same seasonal pattern observed in streamflow was also
evident for groundwater, with the highest electrical conductivity and least
negative isotopic values found during cold or relatively less warm periods,
when the melt of snowpack and ice was limited. Particularly, the application
of a two-component mixing model to data from different springs showed that
the snowmelt contribution to groundwater recharge varied between 21%
(±3%) and 93% (±1%) over the season, and the overall
contribution during the three study years ranged between 58% (±24%)
and 72% (±19%). These results provided new insights into
the isotopic characterization of the study catchment presenting further
understanding of the spatio-temporal variability of the main water sources
contributing to runoff. |
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