Tang et al. (2026) Balancing performance and uncertainty in multi-source evapotranspiration fusion across the Qinling–Daba Mountains, China

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-16
• Authors: Yanhong Tang, Yi He, Rui Yan, Dejing Chen, Lei Zhu, Puxia Wu
• DOI: 10.1016/j.ejrh.2026.103994

Research Groups

• Shaanxi Provincial Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an, China
• College of Urban and Environmental Sciences, Northwest University, Xi'an, China
• College of Computer Science, Northwest University, Xi'an, Shaanxi, China
• Key Laboratory of State Forest Administration on Soil and Water Conservation & Ecological Restoration of Loess Plateau, Shaanxi Academy of Forestry, Xi'an, 710016, China

Short Summary

This study investigates the effects of weighting strategies, bias-correction references, and error dependence on the accuracy and propagated uncertainty of multi-source evapotranspiration (ET) fusion in heterogeneous mountainous regions. The authors integrated seven ET products and compared seven fusion schemes using water-balance-derived ET as a reference.

Objective

• Investigate how different fusion schemes influence ET accuracy, propagated uncertainty, and robustness in complex mountainous environments.
• Evaluate the effects of weighting formulation, bias-correction reference, seasonal conditions, and inter-product error dependence on fusion outcomes.

Study Configuration

• Spatial Scale: The study was conducted at a spatial scale of 0.05° computational grid covering the Qinling–Daba Mountains, China.
• Temporal Scale: The temporal scale ranged from 2004 to 2018, with monthly data used for analysis.

Methodology and Data

• Models used: Seven ET products were integrated: CoSEB, ETCR, FLUXCOM-X-BASE (XBASE), GLEAM4, MERRA-2, PML_V2, and WEB-DHM-SG.
• Data sources: The data sources included satellite remote sensing, reanalysis systems, land surface models, and ground-based measurements.

Main Results

• The original ET products showed strong temporal but moderate spatial consistency.
• Product-mean relative uncertainty ranged from 8% to 21%, compared with 13%–16% among basins.
• Fused products achieved R values of 0.90–0.93, RMSE of 14–20 mm⋅month⁻¹, MAE of 9–15 mm⋅month⁻¹, and KGE mainly between 0.60 and 0.85.

Contributions

• This study provides a comprehensive evaluation of multi-source ET fusion in complex mountainous regions.
• The results highlight the importance of considering weighting formulation, bias-correction reference, seasonal conditions, and inter-product error dependence when designing fusion schemes.

Funding

• No funding information is provided in the paper.

Citation

@article{Tang2026Balancing,
  author = {Tang, Yanhong and He, Yi and Yan, Rui and Chen, Dejing and Zhu, Lei and Wu, Puxia},
  title = {Balancing performance and uncertainty in multi-source evapotranspiration fusion across the Qinling–Daba Mountains, China},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103994},
  url = {https://doi.org/10.1016/j.ejrh.2026.103994}
}