PREMHYCE: an operational tool for low-flow forecasting

Abstract

Many human activities can be strongly impacted by water shortages (freshwater supply, irrigation, electricity production, river navigation, recreation, etc.). It is therefore necessary to anticipate low-flow periods to improve water management while preserving aquatic ecosystems. This is reinforced by the perspective of more severe low-flow periods in the context of ongoing climate change. To answer these challenges, five French institutions have developed an operational low-flow forecasting tool, called PREMHYCE. Produced by a research project initiated in 2011 with the support of the French Office of Biodiversity and the Water and Biodiversity Direction, it has been tested since 2018 in real time on more than a thousand catchments in mainland France and La Reunion Island. PREMHYCE includes five hydrological models implemented on gauged catchments, which assimilate the last flow observations in real time. Flow forecasts are issued daily considering ensembles of rainfall and temperature scenarios (from a meteorological model up to 15 days and from climate archives up to 90 days). The results of the platform are communicated to the operational managers using dedicated communication tools to help them in their decision-making. A web-based visualization interface provides a real-time overview of the observed and forecasted situation.