Open AccessScale Dependence of the Effective Matrix Diffusion Coefficient: Some Analytical Results
Author(s) -
Liu H. H.,
Zhang Y. Q.,
Molz F. J.
Publication year - 2007
Publication title -
vadose zone journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.036
H-Index - 81
ISSN - 1539-1663
DOI - 10.2136/vzj2006.0140
Subject(s) - matrix (chemical analysis) , diffusion , effective diffusion coefficient , coefficient matrix , scale (ratio) , tracer , statistical physics , diffusion process , materials science , thermodynamics , physics , computer science , composite material , medicine , knowledge management , eigenvalues and eigenvectors , innovation diffusion , radiology , quantum mechanics , nuclear physics , magnetic resonance imaging
Matrix diffusion is an important process affecting solute transport in fractured rock, and the matrix diffusion coefficient is a key parameter for describing this process. Previous studies have indicated that effective matrix diffusion coefficient values obtained from a number of field tracer tests are enhanced in comparison with local values and may increase with test scale. In this communication, we develop analytical expressions for the effective matrix diffusion coefficient for two simple fracture–matrix systems and demonstrate that heterogeneities in the rock matrix at different scales may contribute to the scale dependence of the effective matrix diffusion coefficient.