Hydro-meteorological modelling of the Rhone basin: General presentation and objectives

The gaper presents the French national effort undertaken these 5 last years in order to build a hydrological modelisation of the Phone catchment, coup ling the surface and the, atmosphere at regional stale. The modelling strat egy is based on the coupling of the operational surface model (the ISBA SVA T scheme), the snow model (CROCUS) of Meteo-France and the distributed hydr ological model MODCOU developed at Centre d'Informatique Geologique de l'Ec ole Nationale Superieure des Mines de Paris (CIG/ENSMP). As a first step, t he coupled model (called in the following CIRSE) uses prescribed atmospheri c forcing deduced from meteorological analysis. Several high resolution dat abases on a fourteen-year period have been constituted. The first part of t he article presents the meteorological forcing database, the discharges dat abase and the soil and vegetation maps. Then, the first results of CIRSE mo del and its validation on the riverflows are shown. As the coupled model wa s proved to be able to simulate present hydrology characteristics, it was f inally used to conduct a preliminary climate change impact study. The impac t of surface air temperature and precipitation variations on the hydrologic al cycle in a doubling CO2 scenario simulated by the Meteo-France climate G eneral Circulation Model (GCM) are shown. (C) 2001 Elsevier Science Ltd. Al l rights reserved.