Evaluation method dependency of measured saturated hydraulic conductivity

Saturated hydraulic conductivity (Ks) is one of the most important hydraulic properties affecting water flow in soils. Spatial and seasonal variability as well as scale dependency are key factors which make it more difficult to accurately measure the saturated hydraulic conductivity. The uncertainty of the Ks values due to different evaluation methods was investigated using raw measured data obtained on two different Hungarian soils with three different in situ measuring devices (double ring, tension disc and mini disc infiltrometers), as well as with two laboratory methods. Since the very same raw infiltration data could result in significantly different Ks values, we have introduced the evaluation method dependency of the measured Ks values. Our investigations found that the effect of the applied evaluation method for assessing raw measured data can be just as significant as the effect of other factors, such as the scale effect, as well as the spatial and temporal variability. ► The use of grease to avoid wall-effect is recommendable when taking soil samples. ► The van Genuchten SWRC is recommended when using the MDI-Zhang method. ► Wooding's method is recommended when using Tension Disc Infiltrometer. ► An evaluation method dependency of the measured K S values should be introduced.