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Titel |
Effect of the spatial distribution of physical aquifer properties on modelled water table depth and stream discharge in a headwater catchment |
VerfasserIn |
C. Gascuel-Odoux, M. Weiler, J. Molenat |
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 ; 14, no. 7 ; Nr. 14, no. 7 (2010-07-02), S.1179-1194 |
Datensatznummer |
250012362
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Publikation (Nr.) |
copernicus.org/hess-14-1179-2010.pdf |
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Zusammenfassung |
Water table depth and its dynamics on hillslopes are often poorly predicted
despite they control both water transit time within the catchment and solute
fluxes at the catchment outlet. This paper analyses how relaxing the
assumption of lateral homogeneity of physical properties can improve
simulations of water table depth and dynamics. Four different spatial models
relating hydraulic conductivity to topography have been tested: a simple
linear relationship, a linear relationship with two different topographic
indexes, two Ks domains with a transitional area. The Hill-Vi model has been
modified to test these hypotheses. The studied catchment (Kervidy-Naizin,
Western France) is underlain by schist crystalline bedrock. A shallow and
perennial groundwater highly reactive to rainfall events mainly develops in
the weathered saprolite layer. The results indicate that (1) discharge and
the water table in the riparian zone are similarly predicted by the four
models, (2) distinguishing two Ks domains constitutes the best model and
slightly improves prediction of the water table upslope, and (3) including
spatial variations in the other parameters such as porosity or rate of
hydraulic conductivity decrease with depth does not improve the results.
These results underline the necessity of better investigations of upslope
areas in hillslope hydrology. |
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