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| Titel |
Assessing topsoil and bedrock hydrodynamic properties from natural and artificial rainfalls over a 10m2 steep plot in Cevennes area (France) |
| VerfasserIn |
Marko Adamovic, Christophe Bouvier, Pascal Brunet, Pierre-Alain Ayral |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250132241
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| Publikation (Nr.) |
 EGU/EGU2016-12730.pdf |
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| Zusammenfassung |
| Flash floods are feature of Mediterranean climate characterized by heavy rainfalls in a few
hours. Hydrological processes depend on both the topsoil and bedrock properties, which are
still poorly known in the mountainous areas.
Thus, special attention was paid to characterize the water fluxes in the shallow
near-surface area. This study focuses on a 10-m2plot within a granitic hillslope in Cevennes
area. Water content was monitored at several depths (up to 70cm) during both intense
artificial and natural rainfall events, in order to study both infiltration and saturation processes
in both extreme and normal conditions.
Inverse modeling was performed in order to estimate parameters, such as θs, θr, α, n, Ks
associated to the Mualem-Van Genuchten formulation, using the HYDRUS-1D software.
The deep boundary condition was also calibrated to assess the properties of the deep
layers.
Although the topsoil depth is rather small (∼40 cm), the water storage during the rainfalls
was estimated to be some hundreds millimeters, which largely exceeds the topsoil capacity. It
suggests that the weathered area (and maybe the fractured rock area) below the soil, can
have an active role in the water storage and sub-surface flow dynamics. Similar
parameters were used to perform correct simulations under both artificial and natural
rainfalls: thus artificial rainfalls enhance extreme conditions corresponding to flash
floods occurrence, and the identified flux patterns are robust in natural conditions. |
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