EGU2020-19335, updated on 31 Mar 2023
EGU General Assembly 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

PREMHYCE: An operational tool for low-flow forecasting

Pierre Nicolle1, François Besson2, François Bourgin1, Didier François3, Matthieu Le Lay4, Charles Perrin1, Fabienne Rousset2, Dominique Thiéry5, François Tilmant1, Claire Magand6, and Elise Jacob6
Pierre Nicolle et al.
  • 1University Paris-Saclay, INRAE, UR HYCAR, Antony, France (
  • 2Météo-France, Climatology and Climate Service Department, Toulouse, France
  • 3Lorraine University, LOTERR, Metz, France
  • 4EDF-DTG, Grenoble, France
  • 5BRGM, Orléans, France
  • 6French Office for Biodiversity (OFB), Vincennes, France

In many countries, rivers are the primary supply of water. A number of uses are concerned (drinking water, irrigation, hydropower…) and they can be strongly affected by water shortages. Therefore, there is a need of early anticipation of low-flow periods to improve water management. This is strengthened by the perspective of having more severe summer low-flows in the context of climate change. Several French institutes (Irstea, BRGM, Météo-France, EDF and Lorraine University) have been collaborating to develop an operational tool for low-flow forecasting, called PREMHYCE. It is tested in real time since 2017, and implemented on 259 catchments in metropolitan France, in cooperation with operational services which provide streamflow observations and use low-flow forecasts from the tool. PREMHYCE includes five hydrological models which can be calibrated on gauged catchments and which assimilate flow observations. Low-flow forecasts can be issued up to 90 days ahead, based on several inputs scenarios: ECMWF 10-days ensemble forecasts, ensemble streamflow prediction (ESP) using historical climatic data as ensembles of future input scenarios, and a no precipitation scenario. Climatic data (precipitation, evapotranspiration and temperature) are provided by Météo-France with the daily gridded SAFRAN reanalysis on the 1959-2019 period, which includes a wide range of conditions. The tool provides text files and graphical representation of forecasted low-flows, and probability to be under low-flow thresholds provided by users. Outputs from the different hydrological models can be combined within a multi-model approach to improve robustness of the forecastsThe presentation will show the main characteristics of this operational tool, the probabilistic evaluation framework, results on the recent low-flow periods, and how feedbacks from end-users can help improving the tool.

How to cite: Nicolle, P., Besson, F., Bourgin, F., François, D., Le Lay, M., Perrin, C., Rousset, F., Thiéry, D., Tilmant, F., Magand, C., and Jacob, E.: PREMHYCE: An operational tool for low-flow forecasting, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19335,, 2020.


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