A NOTE ON THE USE OF A SIMPLE NUMERICAL MODEL FOR VERTICAL, UNSATURATED FLUID FLOW

Abstract

Wind and Van Doorne (1975) use an exponential approximation for the unsaturated conductivity to derive a simple expression for vertical, unsaturated fluid flow. Richter (1980) makes use of several exponential segments to approximate the unsaturated conductivity, which extends the method to a wider range of soils and moisture contents. However, this leads to a difficulty in the solution and can create a discontinuity in the predicted moisture content-depth profile. This paper demonstrates a method for removing this difficulty and the resulting discontinuity and applies the method to two examples of drainage problems and to infiltration into Yolo light clay.