 |
| Titel |
A stochastic approach for the description of the water balance dynamics in a river basin |
| VerfasserIn |
S. Manfreda, M. Fiorentino |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 12, no. 5 ; Nr. 12, no. 5 (2008-09-17), S.1189-1200 |
| Datensatznummer |
250010879
|
| Publikation (Nr.) |
 copernicus.org/hess-12-1189-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| The present paper introduces an analytical approach for the description of
the soil water balance dynamics over a schematic 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. This equation can
be solved assuming known the spatial distribution of the soil moisture over
the basin transforming the two-dimensional problem in space in a one
dimensional one. This assumption is particularly true in the case of humid
and semihumid environments, where spatial redistribution becomes dominant
producing a well defined soil moisture pattern. The model allowed to derive
the probability density function of the saturated portion of a basin and of
its relative saturation. This theory is based on the assumption that the soil
water storage capacity varies across the basin following a parabolic
distribution and the basin has homogeneous soil texture and vegetation cover.
The methodology outlined the role played by the soil water storage capacity
distribution of the basin on soil water balance. In particular, the resulting
probability density functions of the relative basin saturation were found to
be strongly controlled by the maximum water storage capacity of the basin,
while the probability density functions of the relative saturated portion of
the basin are strongly influenced by the spatial heterogeneity of the soil
water storage capacity. Moreover, the saturated areas reach their maximum
variability when the mean rainfall rate is almost equal to the soil water
loss coefficient given by the sum of the maximum rate of evapotranspiration
and leakage loss in the soil water balance. The model was tested using the
results of a continuous numerical simulation performed with a
semi-distributed model in order to validate the proposed theoretical
distributions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|