Isotope-aided hydrological modeling to enhance process understanding in high-latitude catchments

High-latitude regions are challenging to model due to their inherent data scarcity. This limitation hampers our ability to gain robust process understanding and forecast how these regions will respond to global warming and land-use changes. Additionally, these regions are undergoing rapid changes driven by melting snow and ice with far-reaching implications for downstream areas.

In this study, we demonstrate the value of isotope-aided hydrological modeling in improving process understanding and model reliability. Using data from two well-instrumented high-latitude catchments—the Krycklan Catchment Study and Abisko in Sweden—we developed detailed hydrological models in HYPE (Hydrological Predictions for the Environment). We applied a multi-objective calibration approach that includes stable isotopes of water alongside traditional flow data for model calibration and validation. This approach enhances the robustness of model-internal water source partitioning and provides additional insights beyond flow-only calibration.

This work is part of the Water4All project ISOSCAN, which investigates how stable isotopes of water, collected through Citizen Science initiatives, can advance hydrological modeling. By comparing flow-only calibrated models with isotope-aided multi-objective calibrated models, we evaluate the contribution of stable isotopes in improving model performance. We explore the potential of high-information-content data (such as stable isotopes of water) collected by Citizen Scientists to overcome data scarcity challenges and enhance the reliability of hydrological models in high-latitude regions.