Skip to main content

Soil Water Movement in Vapor and Liquid Phases

Taylor, S.A. and Cary, J.W. (1965) Soil Water Movement in Vapor and Liquid Phases. In: Eckardt, F.E., (ed.) Methodology of Plant Eco-Physiology. UNESCO Arid Zone Res, Vol. XXXV. pp. 159-165.

[img] PDF

Download (553kB)


One of the well-known characteristics of arid region
soils is that the temperature undergoes wide fluctuations
throughout the day and throughout the season.
These temperature variations induce thermal gradients
and temperature differences between locations in the
surface soil. Although the existence of these effects is
well known, their effect on the processes that occur
in the soil is not so well known. One of the problems
that has been of considerable interest in recent years
is the influence of temperature differences upon the
movement of water in the soil. Early investigators
of this problem discovered that there was a net water
flux from warm to cold in soil materials subjected to a
thermal difference, but they became involved in a
controversy as to whether the movement was in the
vapour or liquid phase. Some studies supported the
concept of flow in the vapour phase, and others supported
the concept of flow in the liquid phase. A net
flux of vapour from warm to cold and liquid from
cold to warm was demonstrated in an enclosed and
sealed system of porous material, water, and air by
Krischer and Rohnalter (1940). This was later confirmed
for soil material, using a different technique, by
Gurr, Marshall and Hutton (1952), but they obtained
a vapour diffusion coefficient that was very much greater
than expected on the basis of simple laws of diffusion.
Similar studies in sealed systems, using still
different techniques, were reported by Taylor and
Cavazza (1954), who found that the apparent vapour
diffusion coefficient was ten times larger than expected
on the basis of simple diffusion laws. Subsequently,.
there have been repeated observations of this effect,
and several attempts to explain the phenomena based
on various analyses of simultaneous movement of
water and heat (Philip and Dc Vries. 1957; De Vries,
1958; Derjaguin and Melnikova, 1958).

Item Type: Book Section
NWISRL Publication Number: 0015
Subjects: Soil > Soil water (soil moisture)
Mass Import - autoclassified (may be erroneous)
Depositing User: Dan Stieneke
Date Deposited: 20 Nov 2010 21:54
Last Modified: 15 Mar 2017 22:41
Item ID: 722