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| Titel |
Predicting subsurface stormflow response of a forested hillslope – the role of connected flow paths |
| VerfasserIn |
J. Wienhöfer, E. Zehe |
| 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. 1 ; Nr. 18, no. 1 (2014-01-13), S.121-138 |
| Datensatznummer |
250120248
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| Publikation (Nr.) |
 copernicus.org/hess-18-121-2014.pdf |
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| Zusammenfassung |
Rapid flow processes in connected preferential flow paths are widely
accepted to play a key role in the rainfall–runoff response at the hillslope
scale, but a quantitative description of these processes is still a major
challenge in hydrological research. This paper investigates the approach of
incorporating preferential flow paths explicitly in a process-based model
for modelling water flow and solute transport at a steep forested hillslope.
We conceptualise preferential flow paths as spatially explicit structures
with high conductivity and low retention capacity, and evaluate simulations
with different combinations of vertical and lateral flow paths in
conjunction with variable or constant soil depths against measured discharge
and tracer breakthrough.
Out of 122 tested realisations, six set-ups fulfilled our selection criteria
for the water flow simulation. These set-ups successfully simulated
infiltration, vertical and lateral subsurface flow in structures, and
allowed predicting the magnitude, dynamics and water balance of the
hydrological response of the hillslope during successive periods of
steady-state sprinkling on selected plots and intermittent rainfall on the
entire hillslope area. The number of equifinal model set-ups was further
reduced by the results of solute transport simulations. Two of the six
acceptable model set-ups matched the shape of the observed breakthrough curve
well, indicating that macrodispersion induced by preferential flow was
captured well by the topology of the preferential flow network.
The configurations of successful model set-ups suggest that preferential flow
related to connected vertical and lateral flow paths is a first-order
control on the hydrology of the study hillslope, whereas spatial variability
of soil depth is secondary especially when lateral flow paths are present.
Virtual experiments for investigating hillslope controls on subsurface
processes should thus consider the effect of distinctive flow paths within
the soil mantle. The explicit representation of flow paths in a hydrological
process model was found to be a suitable approach for this purpose. |
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