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Titel |
Controls on the temporal and spatial variability of soil moisture in a mountainous landscape: the signature of snow and complex terrain |
VerfasserIn |
C. J. Williams, J. P. McNamara, D. G. Chandler |
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. 7 ; Nr. 13, no. 7 (2009-07-28), S.1325-1336 |
Datensatznummer |
250011949
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Publikation (Nr.) |
copernicus.org/hess-13-1325-2009.pdf |
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Zusammenfassung |
The controls on the spatial distribution of soil moisture
include static and dynamic variables. The superposition of static and
dynamic controls can lead to different soil moisture patterns for a given
catchment during wetting, draining, and drying periods. These relationships
can be further complicated in snow-dominated mountain regions where soil
water input by precipitation is largely dictated by the spatial variability
of snow accumulation and melt. In this study, we assess controls on spatial
and temporal soil moisture variability in a small (0.02 km2),
snow-dominated, semi-arid catchment by evaluating spatial correlations
between soil moisture and site characteristics through different hydrologic
seasons. We assess the relative importance of snow with respect to other
catchment properties on the spatial variability of soil moisture and track
the temporal persistence of those controls. Spatial distribution of snow,
distance from divide, soil texture, and soil depth exerted significant
control on the spatial variability of moisture content throughout most of
the hydrologic year. These relationships were strongest during the wettest
period and degraded during the dry period. As the catchment cycled through
wet and dry periods, the relative spatial variability of soil moisture
tended to remain unchanged. We suggest that the static properties in complex
terrain (slope, aspect, soils) impose first order controls on the spatial
variability of snow and resulting soil moisture patterns, and that the
interaction of dynamic (timing of water input) and static influences
propagate that relative constant spatial variability through most of the
hydrologic year. The results demonstrate that snow exerts significant
influence on how water is retained within mid-elevation semi-arid catchments
and suggest that reductions in annual snowpacks associated with changing
climate regimes may strongly influence spatial and temporal soil moisture
patterns and catchment physical and biological processes. |
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