Field Determination of Hydraulic Conductivity Above a Water Table With the Double‐Tube Method

Abstract

AbstractTheory and principles of the double‐tube method, as presented in a previous paper, were applied and tested in laboratory and field studies. The former were carried out in a sand box, where the hydraulic conductivity of 3.87 cm. per min. obtained with the double‐tube principle agreed closely with the known conductivity of 4.10 cm. per min.Field equipment and procedures for practical application of the double‐tube method are discussed in detail. A specially developed hole cleaner for obtaining an undisturbed soil surface at the bottom of the auger hole is described. It is shown how sufficient depth of saturation and corresponding consistency in resulting hydraulic conductivity values can be ascertained in the field without calculating the hydraulic conductivity after each set of measurements.Results from the double‐tube method in the field compare favorably with hydraulic conductivity data obtained in the laboratory from soil samples taken at the bottom of the auger hole after completion of the field tests. The double‐tube method appears to be a suitable tool for in situ measurement of hydraulic conductivity of soil that is not saturated prior to the time of measurement.