Vers une plus grande flexibilité temporelle du modèle opérationnel de prévision des crues GRP

Nowadays, flood forecasting is often done at the hourly time step, which is a good compromise between data availability and the necessary resolution to simulate flood events. However, in a number of cases, this fixed time step shows limitations, and shorter (or even larger) time steps are required. Therefore, it is necessary to have hydrological models able to adapt to various time steps. Generally, this adaptation does not limit to a simple change of the length of the time step in the model equations. The time-step dependency must be made explicit in some model parameters, and the model structure must also be adapted to consistently represent processes across time steps. The article presents the adaptation of the GRP hydrological model, which is widely used by flood forecasting services in operational conditions in France, so that it can behave and run consistently at different time steps. The tests were made on a set of 240 French catchments.