TR(BR)-7/98-99 : Estimation of dispersion coefficient from data on soil-column test

Abstract

One of reliable alternatives for estimation of dispersion coefficient is to conduct a tracer movement test in a soil column and analyze the data for dispersion coefficient. In a tracer movement test, the exit concentration distribution (commonly known as break through curve) with time is generally observed for known input concentration which often is in the form of step change in concentration input.

In this report, both a simple method and an optimization method for estimation of dispersion coefficient from data on soil-column test have been evolved. Application of the method have been demonstrated on published data sets. The results indicated that the present methods can estimate dispersion coefficient with reliable accuracy. In the simple method, the calculations are very much simplified using which quick and reliably accurate value of dispersion coefficient can be obtained. Application of the optimization method requires a computer while the calculations for the simple method can easily performed on a simple commercial calculator. A computer program in FORTRAN has been developed for the optimization method.