A Comparative Study to Calculate Hydraulic Conductivity in Ultisols on an East Tennessee Hillslope

This study compares four different methods to measure hydraulic conductivity (K) at two sites on the East Tennessee State University Valleybrook Campus. It compares the K values to each other, to the different K values between the two sites, and to United States Department of Agriculture (USDA) K values. Two field methods, Well Bail Test and Auger Hole Test, and two lab methods, Constant Head Permeameter Test and Grain Size Distribution Test (GSD), were performed on the clay rich Ultisol soils on an East Tennessee hillslope in the Valley and Ridge Physiographic Province. One site was located close to a monitoring well and the other on the floodplain of an existing stream. The Hazen, Alyamani & Sen, and Slichter methods were used to compute K from the GSD Test. The Alyamani & Sen, Slichter, and permeameter methods produced similar K values ranging from 9.52 x 10-6 to 1.25 x 10-3 cm/sec. These are similar to the USDA K values ranging from 9.17 x 10-4 to 2.82 x 10-4 cm/sec. The Hazen method overestimated K and ranged from 8.10 x 10-3 to 1.09 x 10-1 cm/sec. The Well Bail Test yielded a lower K value (ranging from 8.16 x 10-9 to 1.19 x 10-8 cm/sec) than the USDA values as expected for water flow in deeper soil horizons at a depth of 8.50 meters. Comparing these values helped to better understand the difference between various methods to compute the hydraulic conductivity