Li et al. (2026) Reconstructed Evapotranspiration in Northern China: Trends, Drivers, and Ecohydrological Impacts

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

Identification

• Journal: International Journal of Climatology
• Year: 2026
• Date: 2026-10-11
• Authors: Hongyu Li, Yubo Su, Qiang Zhang, Ping Yue, Liang Zhang
• DOI: 10.1002/joc.70627

Research Groups

Not available in the abstract.

Short Summary

This study fuses gridded and in situ evapotranspiration (ET) data to create an improved dataset for northern China (1980-2021), revealing that vegetation greening is the primary driver of increasing ET trends, leading to significant hydrological drying in semi-arid regions despite ecological wetting.

Objective

• To attribute regional evapotranspiration (ET) and assess its impacts on land-atmosphere interactions in climate-sensitive regions, specifically northern China.

Study Configuration

• Spatial Scale: Northern China, including the Loess Plateau, North China Plain, and western Inner Mongolia. Data resolution is 0.25° grid cells.
• Temporal Scale: Monthly from 1980 to 2021.

Methodology and Data

• Models used: Random Forest (for data fusion), XGBoost (for driver attribution), SHAP (SHapley Additive exPlanations) analysis.
• Data sources: Six gridded evapotranspiration (ET) products, in situ flux site measurements, reconstructed monthly 0.25° ET dataset, precipitation data, Normalized Difference Vegetation Index (NDVI).

Main Results

• A new monthly 0.25° ET dataset (1980-2021) for northern China was developed, outperforming original products by reducing cross-validation RMSE from 15.15–22.03 mm month⁻¹ to 11.54 mm month⁻¹.
• Significant increasing ET trends (p < 0.05) were observed on the Loess Plateau and North China Plain, with a mean trend of 13.3 mm (10a)⁻¹ in humid regions.
• Precipitation dominates ET interannual variability in grasslands and bare lands, accounting for 35.4% to 40.6%.
• NDVI drives ET trends over 52% of northern China, making vegetation greening a primary force enhancing ET under warming. Precipitation drives ET trends in only about 5% of the region (bare land in western Inner Mongolia).
• Enhanced ET significantly offsets precipitation-driven water yield gains, particularly in semi-arid regions, where the ET-induced reduction reached -11.4 ± 7.7 mm (10a)⁻¹, exceeding the positive contribution from precipitation (2.3 ± 9.2 mm (10a)⁻¹).
• ET positively contributes to the Evaporative Stress Index (ET/PET) over semi-arid regions, generating a coexistence of ecological wetting and hydrological drying.

Contributions

• Development of a high-performance, fused, long-term (1980-2021), high-resolution (0.25°) monthly ET dataset for northern China.
• Quantitative attribution of the dominant drivers of ET interannual variability and long-term trends using advanced machine learning techniques (XGBoost, SHAP).
• Provision of novel ecological insights into ET changes and their contrasting hydrological impacts, specifically highlighting the role of vegetation greening in driving ET trends and the resulting hydrological drying despite ecological wetting in semi-arid regions.

Funding

Not available in the abstract.

Citation

@article{Li2026Reconstructed,
  author = {Li, Hongyu and Su, Yubo and Zhang, Qiang and Yue, Ping and Zhang, Liang},
  title = {Reconstructed Evapotranspiration in Northern China: Trends, Drivers, and Ecohydrological Impacts},
  journal = {International Journal of Climatology},
  year = {2026},
  doi = {10.1002/joc.70627},
  url = {https://doi.org/10.1002/joc.70627}
}