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Models for estimating capillary rise in a heavy clay soil with a saline shallow water table

Prathapar, S.A. and Robbins, C.W. and Meyer, W.S. and Jayawardane, N.S. (1992) Models for estimating capillary rise in a heavy clay soil with a saline shallow water table. Irrigation Science. 13:1-7.

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Shallow saline water tables underlie large areas
of the clay soils in the Murray basin of Australia.
Accurate estimation of capillary rise is important in formulating
management strategies to avoid degradation of
such soils. Measured capillary rise from a saline water
table was compared with capillary rise estimated by three
mathematical models of varying complexity and input
requirement. A quasi steady state analytical model (QSSAM),
a transient state analytical model (TSAM) and a
numerical model (NM) were used. An undisturbed heavy
clay soil core of 0.75 m diameter and 1.4 m deep was
subjected to a static saline water table at 1.2 m from the
surface. A wheat crop was grown on the core and the
weekly capillary rise from the water table was measured.
The electrical conductivity of a 1 : 2 soil : water extract
was determined at 0.15 m depth intervals before and 21
weeks after the introduction of the saline water table. The
QSSAM did not satisfactorily estimate the initial wetting
of the subsoil and the estimated capillary rise was considerably
lower than the measured values. Capillary rise
estimated by the TSAM was reasonably close to the measured
values, but the weekly rates fluctuated considerably.
The NM estimated capillary rise quite satisfactorily
throughout the experiment. Except near the soil surface,
the electrical conductivity values estimated by the NM
were close to the measured values. For estimating total
capillary rise over large areas, the TSAM is preferred
over the NM because of its fewer input requirements and
shorter execution time.

Item Type: Article
NWISRL Publication Number: 0762
Subjects: Soil
Research methodology
Mass Import - autoclassified (may be erroneous)
Depositing User: Dan Stieneke
Date Deposited: 20 Nov 2010 21:53
Last Modified: 05 Dec 2016 17:25
Item ID: 570