Titre :
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Three-dimensional analysis of infiltration from the disc infiltrometer, 1: A capillary-based theory, 2: Physically based infiltration
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Auteurs :
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K. Smettem ;
J. Parlange ;
P. Ross ;
R. Haverkamp
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Type de document :
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article/chapitre/communication
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Editeur :
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Washington [USA] : AGU, 1994
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Format :
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p. 2925-2935
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Langues:
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= Anglais
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Mots-clés:
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ANALYSE DIMENSIONNELLE
;
INFILTRATION
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Résumé :
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1.--The hydraulic properties of an unsatured homogenous and isotropic soil can be obtained from the unconfined flux out of a disc infiltrometer into the soil over the depth of wetting. The disc infiltrometer is becoming increasingly popular, but methods of analysis have generally relied on the restrictive assumptions of one-dimensional flow at early times or quasi-steady state flow at large times. We provide an approximate analytical expression for three-dimensional unsteady, unconfined flow out of a disc infiltrometer, and this includes the geometric effect of the circular source but ignores gravity. This physically based solution is tested against data obtained from laboratory experiments on repacked material. The results illustrate that the difference between three-dimensional and one-dimensional flow is linear with time. 2.-- In situ measurement of soil hydraulic properties may be achieved by analyzing the unconfined efflux from disc tension infiltrometers, once consistent infiltration equations can be derived. In this paper an analytical, three-dimensional infiltration equation is developed, based on the use of parameters with sound physical meaning and adjustable for varying initial and boundary conditions. The equation is valid over the entire time range. For pratical purposes, a simplified solution is also derived. The full and simplified equations give excellent agreement with published experimental results and are particularly useful for determining soil hydraulic properties through application of inverse procedures.
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Source :
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Water Resources Research, vol Vol. 30, no 11, novembre 1994
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