PREMHYCE: a national platform for low-flow forecasting in France

Improving droughts forecasting - whether meteorological, agricultural, or hydrological - is a major challenge for the protection of natural ecosystems and for many economic sectors, including agriculture, energy production, drinking water supply, navigation, and tourism. To provide public water managers with robust low-flow forecasting tools in a context of climate change, the French Office for Biodiversity (OFB) and the Water and Biodiversity Direction (DEB) have supported, since 2011, an initiative aimed at developing a national operational low-flow forecasting platform. This platform, known as PREMHYCE, is the result of a long-term scientific and technical collaboration between INRAE, Météo-France, the University of Lorraine, BRGM, and EDF (Tilmant et al., 2023).

PREMHYCE relies on five hydrological models and ensembles of meteorological scenarios to produce probabilistic streamflow forecasts, enabling the estimation of risks of falling below low-flow thresholds (typically vigilance, alert, reinforced alert, or crisis levels). Forecast lead times range from a few days to several weeks, depending on management objectives and catchments considered. The platform provides daily streamflow forecasts at more than 1,300 gauging stations across the French hydrographic network, with lead times of up to 90 days. These forecasts are made available to more than fifty operational services across mainland France and Réunion Island. They are used to anticipate low-flow periods within local and national decision-making bodies.

In recent years, the PREMHYCE platform has evolved and been upgraded as part of a research project (ANR CIPRHES, 2021–2025), including developments in meteorological forecasting, hydrological modelling, uncertainty quantification, and improvements of the user interface in close collaboration with end users.

This communication aims to present the PREMHYCE forecasting chain, its main functionalities, its range of applications, and its recent developments.

 

Key words: low-flow forecasting, water management, hydrological modelling

 

Reference:

Tilmant, F., Bourgin, F., François, D., Le Lay, M., Perrin, C., Rousset, F., Vergnes, J.-P., Willemet, J.-M., Magand, C., and Morel, M. (2023). - PREMHYCE, une plateforme nationale pour la prévision des étiages. Sciences Eaux & Territoires. 42, 17–21, https://doi.org/10.20870/Revue-SET.2023.42.7297.

 

Acknowledgements:

This work was financially supported by the French National Research Agency (ANR) (grant ANR-20-CE04-0009) within the CIPRHES project, by the French Office for Biodiversity (OFB) and by the Water and Biodiversity Direction (DEB, at the Ministry for ecology).