Calibration and Reliability in Groundwater
Modelling: Credibility of Modelling
(Proceedings of ModelCARE 2007 Conference, held in
Denmark, September 2007). IAHS Publ. 320, 2008, 220-225.
Impacts of calcite dissolution on seawater intrusion processes in
coastal aquifers: density dependent flow and multi species reactive transport
modelling
RACHIDA BOUHLILA &
EZZEDDINE LAABIDI
Lab. De Modlisation en
Hydraulique et Environnement (LMHE) - Ecole Nationale dIngnieurs de Tunis- BP
37.
Le Belvdre, 1002 Tunis. Tunisia
bouhlila.rachida@enit.rnu.tn
Abstract Several experimental works and real
situations show a calcite dissolution–precipitation mechanism in coastal
aquifers (Andersen et al., 2005; Rezaei, et al., 2005). These processes are governed by calcite equilibrium
displacement in freshwater and seawater mixing zones. They can induce notable
modifications of the hydrodynamic properties, porosities and permeabilities, in
aquifers (Romanov et al.,
2006). A density dependent flow and multi-species geochemical model in porous
media is presented in this paper (Bouhlila, 1999, 2006) extended to carbonate
species (Laabidi, 2007). Salts and brine geochemistry is described according to the Pitzer model (Pitzer et
al.,1984) and a consistent numerical scheme for Darcys velocities
in density dependent flow (Bouhlila, 1999, 2006) is used. The hydrogeochemical model thus written, checked and
validated, is used to simulate flow, solutes transport and calcite
dissolution–precipitation reactions in a calcareous
coastal aquifer with a geometry and
hydrodynamic parameters that correspond to the Henrys problem.
Keywords multi species reactive transport; density dependent flow; calcite dissolution; costal aquifer; Henrys problem