Author(s)

A.P. Belov & T.C. Atkinson

Abstract

Non-Fickian tracer dispersion in a karst conduit embedded in a porous medium A.P. Belov*, T.C. Atkinson* "Department of Mathematics and Computing, University of Glamorgan, Pontypridd, Mid Glamorgan, CF3 7 1DL, UK ^School of Environmental Sciences, University of East Anglia, 77% ABSTRACT Longitudinal dispersion of a tracer slug by the flow along a karst conduit is often assumed to obey Pick's Law, governed by a single dispersion coeffi- cient. Tracer breakthrough curves have often been interpreted on this basis despite empirical evidence of non-Fickian asymmetry and tailing of the tra- cer cloud. A possible cause of this tailing is that tracer diffuses through the wall of the conduit into slow-moving groundwater in the fractured or porous aquifer in which the conduit is embedded. The effects of such behaviour on the time-concentration curve at the end of the conduit are investigated in this study by means of mathematical analysis. An explicit analytical solutio

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