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Unformatted text preview: random aquifer simulations.
Convergence of both inner iterations (CG) and outer iterations (Picard) were carefully
controlled via stopping criteria and a posteriori analyses of convergence rates. We found
that double precision computations were necessary for highly heterogeneous permeabilities.
Finally, in order to overcome convergence problems due to large K contrasts (σlnK>>1), we
introduced a σ-continuation method (homotopy).
The continuation method and other procedures developed in this paper are aimed at a
better understanding of σZSALT(x), i.e., the variability of seawater intrusion in highly
heterogeneous aquifers. A robust perturbation theory is currently being considered for
interpreting the results for σlnK>>1. A previous perturbation theory (Ababou & Al-Bitar
2005) provided a fairly good fit for σlnK up to 1.60. Possibly, the correct interpretation of the
present numerical experiments requires, for σlnK>>1, larger sampling domains (10 million
nodes) and/or multiple replicates (Monte-Carlo). Other numerical developments include
pumping well modelling, and efficient algorithms to deal with irregular 2D and 3D grid
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This document was uploaded on 01/19/2014.
- Winter '14
- The Land, In French