Hydraulic Properties of a Clay Loam Soil and the Field Measurement of Water Uptake by Roots: III. Comparison of Field and Laboratory Data on Retention and of Measured and Calculated Conductivities

Abstract

Soil water characteristics obtained on soil cores in the laboratory at air pressures < 1 bar agreed substantially with pressure‐water content relations determined in the field. Thus, in field studies of soil hydraulics, measurement of either water content or pressure potential may suffice.When the laboratory data were supplemented with a doubletube measurement of the saturated conductivity, the relation between water content and conductivity was calculated using two methods. Of these, the one due to Millington and Quirk gave less accurate agreement with actual field measurements than did the method proposed by Laliberte, Corey and Brooks. The latter method, when based on double‐tube measurements in the field and pressure cells or similar measurements on cores in the laboratory, appears useful.Retention values measured with the pressure membrane method on disturbed soil samples were out of line with both field and core results, even when the disturbing treatments were minimized.

Environmental Geomechanics

“…Green & Corey ( 1971) used this measured data in an evaluation of some predictive methods of determining hydraulic conductivity. This curve was shown to be in 1 good agreement with measured data from Brust et al ( 1968) and Jackson et al ( 1965). This curve was shown to be in 1 good agreement with measured data from Brust et al ( 1968) and Jackson et al ( 1965).…”

Water Pollution

“…Permeabilities can be estimated as (Bear, 1972), (4.2.2) where C is a characterizing constant for soil type with values of 45 for clayey sand and 140 for pure sand, and dis the average pore diameter (Freeze and Cherry, 1979). 4.6 and 4.7, with data from Brust et al (1968);Campbell (1974); Jury and Miller (1974); Nielsen et al (1972);Sophocleous (1979); and, Warrick et al (1971). Experimental data that provide examples of the variations in water conductivity and moisture tension as functions of moisture content in different soil types are shown in Figs.…”

Toward a new parameterization of hydraulic conductivity in climate models: Simulation of rapid groundwater fluctuations in Northern California

“…The choice of a lognormally distributed hydraulic conductivity is not new, as shown in Freeze [] and Delhomme [] and is also supported by experimental data in several studies [ Law , ; Warren et al ., ; Brust et al ., ]. Unlike Gaussian, the lognormal distribution guarantees that K(Θ) is positive definite.…”