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Hydrograph separation using isotopic, chemical and hydrological approaches (Strengbach catchment, France)

Ladouche, Bernard and Probst, Anne and Viville, Daniel and Idir, Samir and Baqué, David and Loubet, M. and Probst, Jean-Luc and Bariac, Thierry Hydrograph separation using isotopic, chemical and hydrological approaches (Strengbach catchment, France). (2001) Journal of Hydrology, vol. 2 (n° 3-4). pp. 255-274.

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Official URL: http://dx.doi.org/10.1016/S0022-1694(00)00391-7

Abstract

The streamflow components were determined in a small catchment located in Eastern France for a 40 mm rain event using isotopic and chemical tracing with particular focus on the spatial and temporal variations of catchment sources. Precipitation, soil solution, springwater and streamwaters were sampled and analysed for stable water isotopes (18O and 2H), major chemical parameters (SO4, NO3, Cl2, Na1, K1, Ca21, Mg21, NH4, H1, H4SiO4, alkalinity and conductivity), dissolved organic carbon (DOC) and trace elements (Al, Rb, Sr, Ba, Pb and U). 18O, Si, DOC, Ba and U were finally selected to assess the different contributing sources using mass balance equations and end-member mixing diagrams. Isotopic hydrograph separation shows that the pre-event water only contributes to 2% at the beginning of the stormflow to 13% at the main peak flow. DOC associated to Si and U to Ba allow to identify the different contributing areas (upper layers of the saturated areas, deep layers of the hillslope and rainwater). The streamflow (70%) originates from the deep layers of the hillslope, the remaining being supplied by the small saturated areas. The combination of chemical (both trace and major elements) and isotopic tracers allows to identify the origin of water pathways. During the first stage of the storm event, a significant part of the runoff (30±39%) comes from the small extended saturated areas located down part of the basin (overland runoff then groundwater ridging). During the second stage, the contribution of waters from the deep layers of the hillslope in the upper subcatchment becomes more significant. The final state is characterised by a balanced contribution between aquifers located in moraine and downslopes. Indeed, this study demonstrates the interest of combining a variety of hydrometric data, geochemical and isotopic tracers to identify the components of the streamwater in such conditions.

Item Type:Article
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Institut National de la Recherche Agronomique - INRA
French research institutions > Institut de Recherche pour le Développement - IRD
Other partners > Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE)
Université de Toulouse > Université Paul Sabatier-Toulouse III - UPS
Other partners > Université Louis Pasteur-Strasbourg I - ULP (FRANCE)
French research institutions > Centre National de la Recherche Scientifique - CNRS
Laboratory name:
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Deposited By: Florence Amor
Deposited On:14 Jun 2010 14:43

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