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| Titel |
A stochastic approach for the description of soil water balance at basin scale: application to semiarid environments |
| VerfasserIn |
Salvatore Manfreda, Andrea Gioia, Vito Iacobellis, Mauro Fiorentino |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250044447
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| Zusammenfassung |
| The present study extends the analytical work proposed by Manfreda (2008) and
Manfreda and Fiorentino (2008) for the description of the soil water balance in a
humid river basin. The model is based on a stochastic differential equation, where
the rainfall forcing is interpreted as an additive noise in the soil water balance.
Spatial heterogeneity of a basin is incorporated by a parabolic function describing the
distribution of soil water storage capacity. This distribution is a key factor for a
correct interpretation of the soil water balance that have been modified proposing a
generalized expression adequate for both humid and arid basins. In the previous
version of the model, the soil water storage distribution was set with a minimum in
zero. This imply that the relative saturated portion of the river basin areas have an
infinitesimal probability to be zero and consequently runoff rate is equal to rainfall rate.
This approach has been generalized adopting a distribution of soil depths bounded
between two non zero-values allowing to reproduce the condition of zero runoff under
some rainfall events. The model, characterized by parameters that depend on soil,
vegetation and basin morphology, allowed to derive analytically the probability
density function of the relative saturation, portion of the saturated area and the
surface runoff of a basin. Its application over a set of river basins belonging to a
semiarid region of Southern Italy provides a formal description of the role played by
climate, soil, and vegetation interactions in relative basin saturation and runoff
production.
References
Manfreda, S., Runoff Generation Dynamics within a Humid River Basin, Nat. Hazard
Earth Sci., 8, 1349-1357, 2008.
Manfreda S., M. Fiorentino, A Stochastic Approach for the Description of the
Water Balance Dynamics in a River Basin, Hydrol. Earth Syst. Sci., 12, 1189-1200,
2008. |
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