A multi-fidelity modelling approach to improve regional-scale assessment of groundwater contribution to headwater dynamics – FutureFlow

Headwater catchments (HWC), the uppermost drainage area of stream networks draining about 60% of the continental surface, are the main sources of freshwater for downstream hydrological systems, influencing natural and human ecosystem services. Despite their importance, current predictions of future hydrological responses to climate change remain highly uncertain at the regional scale. Difficulties arise from the challenges of representing the hidden groundwater contribution to the dynamics, while enabling deployment and parameterization of groundwater flow models capable of capturing the observed dynamics. With water scarcity projected to increase across Europe, there is an urgent need to develop innovative modelling solutions and projection capacities tailored to HWC capable of representing the key contribution of the groundwater system.

The FutureFlow project aims to specifically address these challenges by transferring innovations from software engineering to the field of HWC hydrogeology. The main objective is to develop an adaptive model switch multi-fidelity approach for regional-scale HWC modelling, ensuring well-calibrated and predictive groundwater flow models. This approach uses well-constrained decision algorithms to select and calibrate physically based models with hydrogeological properties that capture current dynamics and forecast future changes. It also aims to extrapolate these calibrated model results to ungauged catchments to identify the hydrogeological factors controlling their vulnerability to climate changes. The innovative modelling platform will leverage state of the art models of different fidelities and automatically deploys them to various geomorphic and geologic contexts at the European scale, using multiple data sources for model parameterisation and enabling automated model uncertainty assessment.

The interdisciplinary consortium includes the Swiss Centre of Hydrogeology and Geothermics at the University of Neuchâtel (UniNE) and the French CNRS (UMR Géosciences Rennes), complemented by experts in software engineering from IRISA–Laboratory for Research and Innovation in Digital Science and Technology also part of CNRS partner, data-model interaction from the University of Basel, hydro-climatology from the Laboratoire de Géologie de l'ENS -PSL, and regional hydrogeological assessment from the French Geological Survey. This collaboration brings together the necessary expertise in climate science, hydrological modeling, quantitative hydrogeology, and software engineering to achieve the research objectives of FutureFlow

In addition to providing significant advances in hydrogeological modelling and software engineering, the project will enable the first assessment of HWC vulnerability to climate change based on a multi-fidelity modelling approach. Ultimately, the results of FutureFlow will provide new insights into the evolution of water resources at the European level in the context of climate change, with critical societal benefits in the perspective of designing sustainable adaptation measures to climate changes tailored to local territorial characteristics.