Geoscience Reference
In-Depth Information
Fig. 9.2
Laboratory set-up to study the problem of sorption experimentally. The graduated cylinder maintains
the water at the point of entry (
x
=
0), at constant pressure in the manner of a Mariotte bottle. At the
start of the experiment (
t
=
0), the water supply through the flexible tubing is opened; after a certain
time
t
, at the end of the experiment, the 1 cm sections of the horizontal soil column tubing can be
rapidly taken apart, to determine their soil water content as
θ
=
θ
(
x
). (From Nielsen
et al
., 1962.)
Fig. 9.3
Soil water content distribution
θ
=
θ
(
x
) in Columbia silt loam, obtained after three different times of
horizontal infiltration by means of the apparatus shown in Figure 9.2, with the pressure at the inlet
maintained at
−
2 hPa (or roughly 2.04 cm of water column). The curve for 740 min is the best fit line
through the data points (circles); the curves for 88 min and 344 min are calculated from the curve for
740 min on the basis of Boltzmann similarity, that is by multiplying it by (88
/
740)
1
/
2
and
(344
/
740)
1
/
2
, respectively. (After Nielsen
et al
., 1962.)
