An Operational Forecasting Snowmelt Model with Objective Calibration: Paper presented at EGS XVIII General Assembly (Wiesbaden, Germany – May 1993)

After a review of existing operational models for daily snowmelt forecasting, an operational oriented one has been developed in order to provide a simple tool for one-to-three-day ahead flow management. The main advantage of this lumped degree-day model lies in the algorithmic development which allows a quick and objective parameter calibration. The proposed iterative algorithm is able to furnish a reduction of the number of parameters and an error criteria plotting which allows to choose an adequate set of them. A case study – La Durance at la Clapière station (2,170 km²) – illustrates the use of this proposed methodology. The case study is not limited to a classical fitting on calibration data and testing on a validation set, but also shows the actual day-to-day one-to-three-day ahead forecast made during spring 1993. The forecasting model capabilities as well as its limits are then discussed.