Modelling diffusion in a heterogeneous rock matrix with a time-domain Lagrangian method and an inversion procedure

A Lagrangian method in time domain is proposed to solve transport by diffusion over large grids such as those extracted from autoradiographs of rock samples. The method is rapid and well suited to simulate out-diffusion experiments in a heterogeneous rock matrix. By coupling with a Gauss–Newton optimiser, it is possible to identify automatically the diffusion coefficients of porous areas in the matrix. This offers a more comprehensive view of a potential transport of contaminants, e.g., after a leak from an underground repository site. To cite this article: F. Delay et al., C. R. Geoscience 334 (2002) 967–973.