Semi-global hydrological modelling by coupled simulation of the variation of water storage in the unsaturated zone and of the piezometric level evolution.

Dominique Thiéry (1)

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

A new type of hydrological model -called "semi-global" has been created to attempt at a better understanding of the physical behaviour of a drainage basin. This model,called "Gardensol", simulates the basin globally, in its spatial extension, but it reproduces, at least approximately, the real phenomena with physical parameters capable of being measured in the field : - vertical permeability at saturation, - residual water content, corresponding to an almost nil vertical infiltration permeability. As it can be calibrated simultaneously on the water content variations in the vadose zone and on the piezometric variations. the model is much more reliable and more robust than a rainfall-aquifer level model where the aquifer levels are reproduced only from a usually badly known storage coefficient. The estimation of the recharge, in particular, must be much more exact and the model can be used by extending data to analyse the resource fluctuations according to the climatic variability. Three application examples are given: * Coupled simulation of the water storage in the unsaturated zone and of the piezometric level at Hezieres-Ies-Clery (Loiret department, France). * Simulation of the water storage during 8 years in a small area of the Orgeval experimental basin of the CEMAGREF, * Coupled simulation of the water storage in the unsaturated zone and of the piezometric level on the Lille-Sainghin (France) experimental site.

Domains: Hydrology; Global Changes

Dominique Thiéry. Semi-global hydrological modelling by coupled simulation of the variation of water storage in the unsaturated zone and of the piezometric level evolution.. International Symposium on Systems Analysis Applied to Management of Water Resources, Oct 1988, Rabat, Morocco. pp.7-11. ⟨hal-01061975⟩