Résumé
Fate and transport of contaminants in aquifers are influenced by geochemical reactions (precipitation/dissolution) and biological activities (biofilm development). If simulations and observations of contaminant behavior are at a large-scale (continuum-scale), processes leading to their degradation occur at a small-scale (pore-scale). In terms of modeling, the complexity of these last processes requires to represent them at their natural scale and to consider computational limitations for large domain simulations. As classical methods for transferring information between scales are not relevant for strongly coupled processes, we aim at creating a new modeling approach combining different representation concepts over different sub-domains. The different models run simultaneously over the different sub-domains and are coupled at the sub-domains interfaces by defining boundary fluxes for each model. Where biogeochemical processes are determinant, a pore-scale representation will be used to describe the involved processes. For the rest of the domain, a continuum representation will be preferred with a level of complexity adapted to the processes characteristics. By optimizing the balance between computational efficiency and representation accuracy, this new approach for modeling contaminant behavior at their trajectory-scale promises the possibility of large domain simulations with an adequate representation of degradation processes.