MODELING ADVECTIVE TRANSPORT IN KARST AQUIFERS USING CONTINUUM MODELS

Standard continuum ground water models are often applied to karst aquifers for management of water quantities allocated to wells and springs. When these models are used to predict advective transport velocities, they generally underestimate the measured velocities obtained through dye trace data. This problem can be attributed to an averaging error that occurs in heterogeneous systems. This miscalculation causes standard continuum models to underestimate velocity values, increasing the error as heterogeneity increases. Thus, karst aquifers, as highly heterogeneous systems, are most poorly represented by continuum models containing this error. A method for improving advective transport predictions is demonstrated using a continuum model of the Barton Springs segment of the Edwards aquifer. This method allows continuum models to be applied to transport in karst with lower transport velocity errors.