Can a multi-model approach improve hydrological ensemble forecasting? A study on 29 French catchments using 16 hydrological model structures

摘要

An operational hydrological ensemble forecasting system based on ameteorological ensemble prediction system (M-EPS) coupled with ahydrological model searches to capture the uncertainties associated with themeteorological prediction to better predict river flows. However, thestructure of the hydrological model is also an important source ofuncertainty that has to be taken into account. This study aims at evaluatingand comparing the performance and the reliability of different types ofhydrological ensemble prediction systems (H-EPS), when ensemble weatherforecasts are combined with a multi-model approach. The study is based on 29catchments in France and 16 lumped hydrological model structures, driven bythe weather forecasts from the European centre for medium-range weatherforecasts (ECMWF). Results show that the ensemble predictions produced by acombination of several hydrological model structures and meteorologicalensembles have higher skill and reliability than ensemble predictions giveneither by one single hydrological model fed by weather ensemble predictionsor by several hydrological models and a deterministic meteorologicalforecast.