Calibration and Reliability in Groundwater Modelling: Credibility of Modelling

(Proceedings of ModelCARE 2007 Conference, held in Denmark, September 2007). IAHS Publ. 320, 2008, 148-153.

 

Calibrating unsaturated model parameters using electrical resistivity tomography imaging

 

F. SLAMA1, E. P. Milnes2 & R. Bouhlila1

1 Laboratoire de Modˇlisation en Hydraulique et Environnement, Ecole Nationale dÕIngˇnieurs de Tunis,
BP 37 Le Belvˇd¸re 1002, Tunis, Tunisie

fairouz.slama@unine.ch

2 Centre of Hydrogeology CHYN, University of Neuch‰tel, 11, rue Emile-Argand, CH-2007 Neuch‰tel, Switzerland

 

Abstract Successive electrical resistivity tomography (ERT) measurements were performed during a controlled infiltration test. Thirty-two electrodes were used with a spacing of 1 m leading to an investigation depth of about 5 m. Four ERT profiles were performed during the infiltration test, each with a time-lapse of one hour. Water, with an electrical conductivity of 9.53 mS cm-1, was infiltrated into a furrow with a constant flux of 0.75 L s-1 for 4 hours. The resistivity difference between the reference and each ERT profiles were computed and mapped to estimate the plume evolution in time. Hydrus2D was used to simulate water flow during the infiltration test and Van GenuchtenÕs soil hydraulic parameters model were calibrated on the measured ERT data set.

 

Key words  unsaturated model; ERT imaging; infiltration test; Van GenuchtenÕs parameters