Assimilation de données d'humidité des sols pour la prévision de crues : comparaison d'un modèle pluie-débit conceptuel et d'un modèle intégrant une interface sol-végétation-atmosphère

Abstract

SUMMARYImproving the accuracy of rainfall-runoff models and in particular their performances in flood prédiction is a key point of continental hydrology. Methods hâve been developed to improve flood prédiction in hydrology based on a better compliance of the model with current observations prior to its use in forecasting mode. This opération has been termed updating in hydrology and assimilation in meteorology. The fundamental idea is that if model prédictions diverge from observations at a given time, there is little chance that future estimations will approach correct values. The improvement then cornes from a correction of the trajectory of the model based on observations during the period preceding the day vvhen a prédiction into the immédiate or long-term future is desired. This can be dealt with by a correction of model parameters, which is usually called "parameter updating".The inability of rainfall-runoff models to produce correct streamflow values generally translates into parameter uncertainty. Parameter calibration is the means used by a model structure to adjust to a given set of data. Therefore, a parameter updating methodology seems to be a natural way to amend errors in streamflow values. In this paper, a spécifie methodology of parameter updating is presented. The main feature of this method is that it does not carry out updating by référence only to récent streamflow observations, as classic procédures do, but also to soil moisture measurements, which can be retrieved daily from TDR (Time Domain Reflectometry) probes. Indeed, it

Vers un modèle hydrologique simplifié pour les études géomécaniques spatialisées

“…Ces études utilisent des techniques d'assimilation de données pluies-débit (Weisse et al, 2003), des données satellitaires (Wagner et al, 1999, Glenn and Carr, 2004, Baghdadi, 2007 ou des modèles de prédiction hydrologiques (Ducrocq et al, 2004). La plupart de ces méthodes, complexes à mettre en oeuvre, donnent une indication quantitative de l'humidité car elles font appel à des modèles physiques calés sur les bilans météo-hydrologiques ou des données de calibration au sol.…”