Automatic calibration of groundwater models by the head gradient method

Dominique Thiéry (1)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)

A groundwater model for flow and transport is reliable only if it is properly calibrated on observations. The best way to ensure a high predictive capability is to limit the number of parameters by defining homogeneous zones. These zones may be defined by an inverse model based on the gradient method. This paper describes a new scheme of inverse model for irregular finite difference 3D models in steady-state. The method determines, in each grid cell, the modification of hydraulic conductivity necessary to adjust the computed head gradients to the observed ones and yields the hydraulic conductivity in the centre of each grid cell. The stability of the results is forced through an optimization scheme simultaneously minimizing the differences of hydraulic conductivity between adjacent grid cells. After determination of the hydraulic conductivity, a procedure derives automatically optimal clusters of values defining geographical zones where homogeneous values of hydraulic conductivity may be imposed. The inverse modelling scheme is operational and applications to four real aquifer systems are presented.

Domaines: Hydrologie; Milieux et Changements globaux

Dominique Thiéry. Automatic calibration of groundwater models by the head gradient method. Tallinn Conference, GQM93, 1993, Groundwater Quality Management, Sep 1993, Tallinn, Estonia. pp. 281-292. ⟨hal-01061969⟩