CHOICE OF DISPERSION COEFFICIENTS IN REACTIVE TRANSPORT CALCULATIONS ON SMOOTHED FIELDS

Theory for covariance method and analytical expressions of effective dispersion for comparison. Two-dimensional heterogeneous log-conductivity field are considered. Mixing of solutes and its approximation by effective dispersion for a point-like injection is developed. The macrodispersion and effective dispersion tensors give the expected amount of plume spreading and mixing in aquifers described by the geostatistical parameters . Application to reactive transport at tests cases. Comparison between the fully resolved fields, the kriged field and a equivalent uniform homogeneous field . Discussions on the hypothesis that effective dispersion coefficient of a conservative tracer is an adequate measure of dispersive mixing in heterogeneous aquifers.