Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment

Multiple water sources and the physiographic heterogeneity of glacierized catchments hamper a complete conceptualization of runoff response to meltwater dynamics. In this study, we used environmental tracers (stable isotopes of water and electrical conductivity) to obtain new insight into the hydrol...

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Main Authors: D. Penna, M. Engel, G. Bertoldi, F. Comiti
Format: Article
Language:English
Published: Copernicus Publications 2017-01-01
Series:Hydrology and Earth System Sciences
Online Access:http://www.hydrol-earth-syst-sci.net/21/23/2017/hess-21-23-2017.pdf
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author D. Penna
M. Engel
G. Bertoldi
F. Comiti
author_facet D. Penna
M. Engel
G. Bertoldi
F. Comiti
author_sort D. Penna
collection DOAJ
description Multiple water sources and the physiographic heterogeneity of glacierized catchments hamper a complete conceptualization of runoff response to meltwater dynamics. In this study, we used environmental tracers (stable isotopes of water and electrical conductivity) to obtain new insight into the hydrology of glacierized catchments, using the Saldur River catchment, Italian Alps, as a pilot site. We analysed the controls on the spatial and temporal patterns of the tracer signature in the main stream, its selected tributaries, shallow groundwater, snowmelt and glacier melt over a 3-year period. We found that stream water electrical conductivity and isotopic composition showed consistent patterns in snowmelt-dominated periods, whereas the streamflow contribution of glacier melt altered the correlations between the two tracers. By applying two- and three-component mixing models, we quantified the seasonally variable proportion of groundwater, snowmelt and glacier melt at different locations along the stream. We provided four model scenarios based on different tracer signatures of the end-members; the highest contributions of snowmelt to streamflow occurred in late spring–early summer and ranged between 70 and 79 %, according to different scenarios, whereas the largest inputs by glacier melt were observed in mid-summer, and ranged between 57 and 69 %. In addition to the identification of the main sources of uncertainty, we demonstrated how a careful sampling design is critical in order to avoid underestimation of the meltwater component in streamflow. The results of this study supported the development of a conceptual model of streamflow response to meltwater dynamics in the Saldur catchment, which is likely valid for other glacierized catchments worldwide.
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spelling doaj.art-98647432745d48fbbe4f8730767db66d2022-12-22T02:41:52ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382017-01-01211234110.5194/hess-21-23-2017Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchmentD. Penna0M. Engel1G. Bertoldi2F. Comiti3Department of Agricultural, Food and Forestry Systems, University of Florence, via San Bonaventura 13, 50145 Florence, ItalyFaculty of Science and Technology, Free University of Bozen-Bolzano, Piazza dell' Università 5, 39100 Bolzano, ItalyInstitute for Alpine Environment, EURAC – European Academy of Bolzano/Bozen, viale Druso 1, 39100 Bolzano, ItalyFaculty of Science and Technology, Free University of Bozen-Bolzano, Piazza dell' Università 5, 39100 Bolzano, ItalyMultiple water sources and the physiographic heterogeneity of glacierized catchments hamper a complete conceptualization of runoff response to meltwater dynamics. In this study, we used environmental tracers (stable isotopes of water and electrical conductivity) to obtain new insight into the hydrology of glacierized catchments, using the Saldur River catchment, Italian Alps, as a pilot site. We analysed the controls on the spatial and temporal patterns of the tracer signature in the main stream, its selected tributaries, shallow groundwater, snowmelt and glacier melt over a 3-year period. We found that stream water electrical conductivity and isotopic composition showed consistent patterns in snowmelt-dominated periods, whereas the streamflow contribution of glacier melt altered the correlations between the two tracers. By applying two- and three-component mixing models, we quantified the seasonally variable proportion of groundwater, snowmelt and glacier melt at different locations along the stream. We provided four model scenarios based on different tracer signatures of the end-members; the highest contributions of snowmelt to streamflow occurred in late spring–early summer and ranged between 70 and 79 %, according to different scenarios, whereas the largest inputs by glacier melt were observed in mid-summer, and ranged between 57 and 69 %. In addition to the identification of the main sources of uncertainty, we demonstrated how a careful sampling design is critical in order to avoid underestimation of the meltwater component in streamflow. The results of this study supported the development of a conceptual model of streamflow response to meltwater dynamics in the Saldur catchment, which is likely valid for other glacierized catchments worldwide.http://www.hydrol-earth-syst-sci.net/21/23/2017/hess-21-23-2017.pdf
spellingShingle D. Penna
M. Engel
G. Bertoldi
F. Comiti
Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
Hydrology and Earth System Sciences
title Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
title_full Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
title_fullStr Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
title_full_unstemmed Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
title_short Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
title_sort towards a tracer based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment
url http://www.hydrol-earth-syst-sci.net/21/23/2017/hess-21-23-2017.pdf
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