Approche par modélisation PLUIE-DEBIT pour la connaissance régionale de la ressource en eau : application à la moitié du territoire français

Using a monthly rainfall-runoff modelling approach in the southern half of France

Cemagref Aix-en-Provence 3275, route cézanne, CS 40061, 13182 Aix-en-Provence Cedex 5

Auteur de correspondance : nathalie.folton@cemagref.fr

Abstract

The aim of this study was to provide a means of determining reference low flows (the mean annual discharge and the 5-year return period mean monthly flow) at any point in the hydrographic network in the southern half of France, using a continuous monthly rainfall-runoff modelling approach. The model adopted here has two parameters. To take into snow or ice influences in mountainous catchments, a monthly snowmelt modelling was added. The accuracy of the calibrated model was found to be excellent for assessing the mean annual discharge, and limited errors were observed in predicting low flows. A regionalisation procedure was performed for the two parameters. This methodology and the data base were built-in in a convivial software. The user has a general tool which synthesizes the whole of the hydrological information of the network of measurement and it is possible to very quickly treat a great number of hydrological problems related to the water resource, with its seasonal and interannual variability. From the simulated flows time series, it is possible to approach the dimensioning of dams, and the statistical treatments associated propose to deduce the hydrological variables of reference.