Contribution des images radar ERS à la modélisation hydrologique du Coët-Dan par TopModel

Using radar ERS images for the hydrological modelling of Coët-Dan with TopModel

Ecole inter-Etats d'Ingénieurs de l'Equipement Rural, E.I.E.R.

Abstract

Distributed models generally result in multiple acceptable parametrisations with respect to the fit of the simulations to the discharge, yet each parametrisation implies a different internal hydrological behaviour. Hence, new data are required to further constrain and validate distributed models. Since these last thirty years have revealed the major role of the saturated areas dynamics under the humid and temperate climates, the saturated area extension appears as an essential information with this respect, and the radar imagery the most promising technology to furnish the expected specialised data. This paper presents the main results of a study of the French Coet-Dan catchment (Gineste, 1998), which aims to extract from ERS radar images an objective distributed measure of an internal state variable of the catchment (i. e. the saturated area extent), in order to validate and eventually improve TopModel simulations.