Field Evaluation of the New Philip-dunne Permeameter for Measuring Saturated Hydraulic Conductivity

FIELD and laboratory methodologies for measuring saturated hydraulic conductivity (Ks ) have been the focus of much attention because Ks is recognized to be one of the most sensitive parameters in predictive hydrological models.Direct measurements are preferred for its determination because indirect methods,usually based on soil textural characteristics combined with aggregate analyses, do not always lead to reliable results (Kutilek and Nielsen, 1994). In addition, Ks values exhibit large variability in soils (Warrick and Nielsen, 1980; Jury et al., 1991). This means that a large number of samples is usually required to estimate the mean value of the population (Warrick and Nielsen, 1980). Field variability and measuring technique are, therefore, two important issues when determining the effective value of Ks. A number of laboratory (Klute and Dirksen, 1986) and field methods (Amoozegar and Warrick, 1986; Elrick and Reynolds, 1992; Ankeny, 1992) have been proposed to measure this soil property, varying in simplicity and applicability with the scenario studied (Dorsey et al., 1990; Gallichant et al., 1990; Gupta et al., 1993). Laboratory methods,usually based on a simple application of Darcy’s law in one dimension,have the adFIELD EVALUATION OF THE NEW PHILIP-DUNNE PERMEAMETER FOR MEASURING SATURATED HYDRAULIC CONDUCTIVITY