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| Titel |
An analytical model for soil-atmosphere feedback |
| VerfasserIn |
B. Schaefli, R. J. Ent, R. Woods, H. H. G. Savenije |
| 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 ; 16, no. 7 ; Nr. 16, no. 7 (2012-07-05), S.1863-1878 |
| Datensatznummer |
250013354
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| Publikation (Nr.) |
 copernicus.org/hess-16-1863-2012.pdf |
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| Zusammenfassung |
Soil-atmosphere feedback is a key for understanding the hydrological cycle
and the direction of potential system changes. This paper presents an
analytical framework to study the interplay between soil and atmospheric
moisture, using as input only the boundary conditions at the upstream end of
trajectory,
assuming advective moisture transport with average wind speed along
this
trajectory and vertical moisture exchange with the soil compartment of
uniform vertical properties. Precipitation, evaporation from interception and
runoff are assumed to depend through simple functional relationships on the
soil moisture or the atmospheric moisture. Evaporation from soil moisture
(including transpiration) depends on both state variables, which introduces a
nonlinear relationship between the two compartments. This nonlinear
relationship can explain some apparently paradoxical phenomena such as a
local decrease of precipitation accompanied by a runoff increase.
The solutions of the resulting water balance equations correspond to
two different spatial moisture regimes showing either an increasing or a
decreasing atmospheric moisture content along a trajectory starting at the coast, depending on boundary
conditions and parameters. The paper discusses how different model parameters
(e.g. time scales of precipitation, evaporation or runoff) influence these
regimes and how they can create regime switches. Such an analysis has
potential to anticipate the range of possible land use and climate changes or
to interpret the results of complex land-atmosphere interaction models. Based
on derived analytical expressions for the Horton index, the Budyko curve and
a precipitation recycling ratio, the analytical framework opens new
perspectives for the classification of hydrological systems. |
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