Tracer Experiments on Field Scale for Parameter Estimation to calibrate Numerical Transport Models

Abstract

In September 2001 a tracing experiment has been worked out at the groundwater test field “Wagna” (400 * 300 m in the Mur valley aquifer system) using 75 kg of sodium bromide as tracer and injected during 20 minutes at the groundwater table (pulse injection). Due to the density of the solute the tracer has been distributed over the whole aquifer depth in a very short time.

For estimating the longitudinal dispersivity an analytical model for calibrating Peclet’ Typecurves on measured tracer breakthrough curves has been used. Transversal dispersivity was estimated using 2D-analytical model calibration. The results of parameter estimation on the field scale are compared to the results of a 2D-numerical bromide transport model for the test field based on a transient groundwater flow model.