A first attempt at modelling groundwater flow and mass transport in the far field

The purpose of this study is to identify and then to model the present transfer of groundwater which might set in motion elements produced in the reaction zone. Consequently, the first stage of this study consisted of a hydrochemical overview of the Oklo-Okelobondo site into which all previous and current information, gathered during missions in September 1990 and June 1991 was integrated. In the second stage of the study, a preliminary hydrodynamic model was built. In a plausible context and based on the collected data, the study area, the drainage of the domain and the aquifer layers were defined and a conceptual hydrogeological flow pattern proposed. The data made it possible to begin the hydrodynamic modelling of current migration basing it on a pattern of groundwater circulation and bearing in mind the morphology of the soil surface and of the geological strata and taking into account the first results of the hydrochemical analyses. (author). 7 refs., 1 tab