Technical ArticlesESTIMATION OF SOIL HYDRAULIC PROPERTIES WITH THE CONE PERMEAMETER: FIELD STUDIESKodešová, Radka1; Ordway, Sondra E.1; Gribb, Molly M.1; Šimůnek, Jiří2Author Information 1Department of Civil & Environmental Engineering, University of South Carolina, 300 Main St., Columbia, SC 29208. Dr. Gribb is corresponding author. E-mail: [email protected] 2U.S. Salinity Laboratory, USDA-ARS, 450 W. Big Spring Rd., Riverside, CA 92507. Received Jan. 12, 1999; accepted April 16, 1999. Soil Science: August 1999 - Volume 164 - Issue 8 - p 527-541 Buy Abstract We present field application of the cone permeameter method for estimating soil hydraulic properties: the soil-moisture characteristic curve, θ(h), and the hydraulic conductivity function, K(h). The cone permeameter was designed to inject water into the soil under known pressure. The cumulative inflow volume and pressure heads measured with tensiometer rings at two locations above the water source are recorded in time. The observed data sets are analyzed using an inverse modeling method to predict the soil hydraulic properties. The device was field-tested for the first time in two types of sandy soil. Tests were always conducted with two sequentially applied pressure heads of different magnitudes for different experimental runs. After the water source was shut off, tensiometer measurements were continued to monitor the redistribution of water in the soil. To study the impact of one or two steps of applied pressure head on estimates of wetting soil hydraulic properties, we carried out numerical inversions for data from the injection (wetting) part of experiment, first with only one supply pressure head and then with two supply pressure heads. For selected tests we analyzed data from the entire experiment to investigate hysteresis of the soil hydraulic properties. The resulting soil hydraulic properties correspond well with those obtained with standard techniques. © 1999 Lippincott Williams & Wilkins, Inc.