Gupta et al. (2026) Balancing subsurface complexity and model simplicity: How much spatially distributed field data is needed to simulate streamflow in a subalpine critical zone

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-09-23
• Authors: Aniket Gupta, Jean‐Martial Cohard, Alix Reverdy, Romain Biron, Catherine Coulaud, Hervé Denis, Marc Descloîtres, Thierry Dumont, Stéphane Garambois, Basile Hector, Jean‐Pierre Vandervaere, Didier Voisin
• DOI: 10.1016/j.jhydrol.2026.136455

Research Groups

• Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
• Université Grenoble Alpes, CNRS, IRD, Institut des Géosciences de l’Environnement (IGE), UMR 5001, Grenoble, France
• Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, ISTerre, 38000 Grenoble, France

Short Summary

This study investigates the representation of subsurface heterogeneity in a critical zone hydrological model using geophysical data and evaluates its impact on streamflow simulation. The results show that incorporating geophysical measurements enhances subsurface characterization and water flux estimation, even when using a simplified subsurface model.

Objective

• To investigate how much spatially distributed field data is needed to simulate streamflow in a subalpine critical zone.
• To evaluate the performance of different subsurface configurations on streamflow simulation.

Study Configuration

• Spatial Scale: 15.28 ha subalpine catchment at Lautaret Pass, French Alps.
• Temporal Scale: One complete hydrological year (2019–2020).

Methodology and Data

• Models used: ParFlow-CLM, a surface-subsurface coupled distributed hydrological model.
• Data sources: Geophysical data from frequency electromagnetic (FEM), electrical resistivity tomography (ERT), and ground penetrating radar (GPR) measurements.

Main Results

• The heterogeneous 3-layer deep soil configuration (HT-3 L-DS) that includes all the information interpreted from the geophysical surveys is the most accurate in predicting the observed streamflow response.
• The simulations show that 3-layer configurations are necessary to accurately represent subsurface heterogeneity and water flux estimation.

Contributions

• This study highlights the importance of incorporating geophysical measurements into hydrological models to enhance subsurface characterization and water flux estimation.
• The results demonstrate that a simplified subsurface model can be used when grounded in reliable field data, but heterogeneous models perform better in capturing snowmelt amplitude, baseflow, evapotranspiration, and surface heterogeneities.

Funding

• This research was funded by the following projects and programs:
  • [Insert funding information]

Citation

@article{Gupta2026Balancing,
  author = {Gupta, Aniket and Cohard, Jean‐Martial and Reverdy, Alix and Biron, Romain and Coulaud, Catherine and Denis, Hervé and Descloîtres, Marc and Dumont, Thierry and Garambois, Stéphane and Hector, Basile and Vandervaere, Jean‐Pierre and Voisin, Didier},
  title = {Balancing subsurface complexity and model simplicity: How much spatially distributed field data is needed to simulate streamflow in a subalpine critical zone},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136455},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136455}
}