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| Titel |
Stream function of a perched water table in a sloping gradually layered soil: effect of the soil anisotropy on the flow patterns |
| VerfasserIn |
S. Barontini, M. Peli, R. Ranzi |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250069497
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| Zusammenfassung |
| Perched water tables in the upper soil layers are an important landslides triggering
mechanism and the knowledge of their properties is relevant in view of slope stability
analyses. During long lasting infiltration processes at low rate, after the imbibition transitories
vanished, an important role on the formation of a perched water table is played by the profile
of the hydraulic conductivity at saturation Ks.
In this paper, as a part of a wider theoretical investigation which aims at describing the
effect of gradually decreasing Ks with depth on the steady soil–water flow, the flow field
taking place within a perched water table lying on a sloping capillary barrier is described and
the corresponding Lagrange stream function is presented. The investigated soil
is considered a priori anisotropic. At the bottom of the domain, for the sake of
continuity of the total hydraulic head, saturation conditions are assumed. The analytical
solution of the flow field was derived with the hypothesis of uniform flow along the
slope.
The flow patterns revealed that the water infiltrating at the upper surface of the perched
water table rapidly leaks toward the underlying soil. The length of the paths is sensitive to the
decrease of the conductivity at saturation and it increases with the soil anisotropy. Anyway it
still remains limited so that, if the slope is long enough, the uniform flow hypothesis can be
considered a reliable approximation of the water flow within a long central branch of the
slope. |
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