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Titel |
Parametrization of the increase of the aeolian erosion threshold wind friction velocity due to soil moisture for arid and semi-arid areas |
VerfasserIn |
F. Fécan, B. Marticorena, G. Bergametti |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 17, no. 1 ; Nr. 17, no. 1, S.149-157 |
Datensatznummer |
250013652
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Publikation (Nr.) |
copernicus.org/angeo-17-149-1999.pdf |
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Zusammenfassung |
Large-scale simulation of the soil-derived
dust emission in semi-arid regions needs to account for the influence of the
soil moisture on the wind erosion threshold. Soil water retention consists of
molecular adsorption on the soil grain surface and capillary forces between the
grain. Interparticle capillary forces (characterized by the moisture tension)
are the main factor responsible for the increase of the wind erosion threshold
observed when the soil moisture increases. When the soil moisture content is
close to but smaller than the maximum amount of adsorbed water, w'
(depending on the soil texture), these capillary forces are considered as not
strong enough to significantly increase the erosion threshold. An expression of
the moisture tension as a function of soil moisture and w' is derived
from retention curves. From this expression, a parametrization of the ratio of
the wet to dry erosion thresholds has been developed as a function of soil
moisture and soil texture. The coefficients of this parametrization have been
determined by using experimental data from the literature. An empirical
relationship between w' and soil clay content has been established. The
erosion threshold ratios simulated for different soil textures were found to be
in good agreement with the experimental data.
Key words. Atmospheric composition and structure
(Aerosols and particles) · Hydrology (soil moisture) |
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