A diffusion exchange model for solute movement in fissured porous rock

Abstract
Summary: A model of solute movement in an idealized, fissured, porous medium, involving diffusion exchange between mobile fissure-water and immobile pore-water, is formulated mathematically and solved numerically for a range of values of the input parameters. The insight gained into this mechanism of solute movement is of relevance in predicting the migration of the more soluble pollutants in the major British aquifers, and is of particular significance to the interpretation of the distribution of tritium and nitrate in the unsaturated zone of the Chalk beneath arable land.