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| Titel |
Modelling runoff at the plot scale taking into account rainfall partitioning by vegetation: application to stemflow of banana (Musa spp.) plant |
| VerfasserIn |
J.-B. Charlier, R. Moussa, P. Cattan, Y.-M. Cabidoche, M. Voltz |
| 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 ; 13, no. 11 ; Nr. 13, no. 11 (2009-11-12), S.2151-2168 |
| Datensatznummer |
250012054
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| Publikation (Nr.) |
 copernicus.org/hess-13-2151-2009.pdf |
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| Zusammenfassung |
| Rainfall partitioning by vegetation modifies the intensity of rainwater
reaching the ground, which affects runoff generation. Incident rainfall is
intercepted by the plant canopy and then redistributed into throughfall and
stemflow. Rainfall intensities at the soil surface are therefore not
spatially uniform, generating local variations of runoff production that are
disregarded in runoff models. The aim of this paper was to model runoff at
the plot scale, accounting for rainfall partitioning by vegetation in the
case of plants concentrating rainwater at the plant foot and promoting
stemflow. We developed a lumped modelling approach, including a stemflow
function that divided the plot into two compartments: one compartment
including stemflow and the related water pathways and one compartment for the
rest of the plot. This stemflow function was coupled with a production
function and a transfer function to simulate a flood hydrograph using the
MHYDAS model. Calibrated parameters were a "stemflow coefficient", which
compartmented the plot; the saturated hydraulic conductivity (Ks),
which controls infiltration and runoff; and the two parameters of the
diffusive wave equation. We tested our model on a banana plot of
3000 m2 on permeable Andosol (mean Ks=75 mm h−1)
under tropical rainfalls, in Guadeloupe (FWI). Runoff simulations without and
with the stemflow function were performed and compared to 18 flood events
from 10 to 140 rainfall mm depth. Modelling results showed that the stemflow
function improved the calibration of hydrographs according to the error
criteria on volume and on peakflow, to the Nash and Sutcliffe coefficient,
and to the root mean square error. This was particularly the case for low
flows observed during residual rainfall, for which the stemflow function
allowed runoff to be simulated for rainfall intensities lower than the
Ks measured at the soil surface. This approach also allowed us to
take into account the experimental data, without needing to calibrate the
runoff volume on Ks parameter. Finally, the results suggest a
rainwater redistribution module should be included in distributed runoff
models at a larger scale of the catchment. |
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