Nimr et al. (2026) Stable Water Isotopes Improve Calibration and Flow Path Identification in Integrated Hydrological Models

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water Resources Research
• Year: 2026
• Date: 2026-07-01
• Authors: Omar Ashraf Nimr, Hannu Marttila, Anna Autio, Pertti Ala‐aho
• DOI: 10.1029/2025wr042007

Research Groups

• Department of Hydrology, University of Colorado Boulder
• Department of Earth Sciences, University of Geneva

Short Summary

This study investigates the impact of incorporating stable water isotopes (δ18O) into calibration targets for integrated surface-subsurface hydrological models (ISSHM), demonstrating improved parameter identifiability and model realism.

Objective

• Investigate the effect of combining hydrometric and isotopic targets on parameter sensitivity, calibration, and flow path inference in ISSHM.

Study Configuration

• Spatial Scale: Sub-arctic Pallas catchment
• Temporal Scale: Long-term (calibration period not specified)

Methodology and Data

• Models used: HydroGeoSphere model
• Data sources: Hydrometric data (streamflow Q, groundwater levels GWL), stable water isotopes (δ18O in streamwater)

Main Results

• Combining hydrometric and isotopic targets led to greater recharge via rapid deep percolation and narrower parameter uncertainty.
• δ18O-only calibration reproduced similar core internal dynamics but yielded the widest uncertainty bounds.

Contributions

• This study demonstrates the value of integrating stable water isotope information (δ18O) into ISSHM calibration, improving parameter identifiability and model realism.

Funding

• Not specified in the provided text.

Citation

@article{Nimr2026Stable,
  author = {Nimr, Omar Ashraf and Marttila, Hannu and Autio, Anna and Ala‐aho, Pertti},
  title = {Stable Water Isotopes Improve Calibration and Flow Path Identification in Integrated Hydrological Models},
  journal = {Water Resources Research},
  year = {2026},
  doi = {10.1029/2025wr042007},
  url = {https://doi.org/10.1029/2025wr042007}
}