Measuring saturated hydraulic conductivity and sorptivity using twin rings

Abstract

A method of measuring, with minimal soil disturbance, the saturated hydraulic conductivity and sorptivity of field soil is presented and discussed. It involves measuring the steady-state infiltration of ponded water from two rings, of different radii, that have been lightly pressed into the soil surface. The method is based on Wooding's solution for steady infiltration from a shallow, circular pond. Criteria for selecting ring radii are discussed. Results for three field soils are found to give consistent values for the conductivity and sorptivity.