Three-dimensional analysis of infiltration from the disk infiltrometer: 3. Parameter estimation using a double-disk tension infiltrometer

Smettem, K.R.J.ORCID: 0000-0003-2650-4429, Ross, P.J., Haverkamp, R. and Parlange, J.Y. (1995) Three-dimensional analysis of infiltration from the disk infiltrometer: 3. Parameter estimation using a double-disk tension infiltrometer. Water Resources Research, 31 (10). pp. 2491-2495.

Abstract

A double-disk tension infiltrometer is developed to measure simultaneously one-dimensional (1-D) and three-dimensional (3-D) infiltration subject to identical initial and boundary conditions. The hypothesis that cumulative three-dimensional infiltration is proportional to the square root of time is incorrect after a few seconds, and in consequence, estimates of sorptivity based on this hypothesis are in error. In contrast, sorptivity calculations using a recently developed 3-D infiltration equation that includes the edge effects of the disk give accurate estimates of sorptivity. The difference between 3-D and 1-D cumulative infiltration is used to calculate the value of an additional infiltration parameter from the double-disk experiment. This parameter, together with the sorptivity, provides the information required to calculate the contribution of gravitational flow during three-dimensional infiltration. It is shown that estimation of hydraulic conductivity using a quasi-steady-state solution may not be justified when 3-D infiltration is dominated by capillary flow effects. Finally, an analysis of the different timescales governing disk infiltrometer experiments under most practical circumstances is provided. A simple expression is given for the time at which the infiltration rate is within a specified amount of the final steady rate.

Item Type:	Journal Article
Publisher:	American Geophysical Union
Copyright:	© American Geophysical Union.
URI:	http://researchrepository.murdoch.edu.au/id/eprint/38255

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