Cao et al. (2026) Direct and indirect impact assessments of climate changes and human activities on runoff changes in 31 source catchments of Yellow River Basin, China

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-01-15
• Authors: Chengqi Cao, Yongyong Zhang, Kun Peng, Qi Tang, Yongqiang Zhang, Guoqing Wang
• DOI: 10.1016/j.jhydrol.2026.134974

Research Groups

• Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences
• University of Chinese Academy of Sciences
• Xinjiang and Raohe Hydrology and Water Resources Monitoring Center
• State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute

Short Summary

This study comprehensively assessed both the direct and indirect impacts of climate change and human activities on runoff changes in 31 source catchments of the Yellow River Basin, revealing that human activities primarily drive changes in underlying surface conditions, while the direct impact of climate change is the largest contributor to runoff alterations.

Objective

• To comprehensively assess both the direct and indirect impacts of climate changes and human activities on runoff changes, including their effects on underlying surface conditions and the subsequent consequences for runoff changes.

Study Configuration

• Spatial Scale: 31 source catchments in the upper and middle reaches of the Yellow River Basin, China, specifically covering the Yellow River Source Region (YRSB), Wei River Basin (WRB), and Yiluo River Basin (YRB).
• Temporal Scale: 1995–2022 (post-change period compared to a pre-change period).

Methodology and Data

• Models used: Improved Budyko framework, elasticity coefficient method, principal component regression.
• Data sources: Not explicitly detailed in the provided text, but implied to be hydrological and meteorological observations for runoff, precipitation, potential evapotranspiration, temperature, and irrigation water.

Main Results

• During 1995–2022, the mean annual runoff changes in the post-change period ranged from −24.0 to 129.9 mm across the 31 source catchments compared to the pre-change period.
• The underlying surface parameter 'n' in the Budyko model ranged from 0.4 to 3.8, with lower values predominantly found in the Yellow River Source Region (YRSB).
• Sensitivity analysis indicated that parameter 'n' was most sensitive to potential evapotranspiration, particularly in the Yiluo River Basin (YRB).
• Runoff changes exhibited the greatest sensitivity to precipitation, with the highest sensitivity observed in the Wei River Basin (WRB).
• Changes in parameter 'n' were primarily attributed to human activities (77.4%) rather than climatic factors (22.6%), with irrigation water (22.6%) and temperature (8.4%) showing the largest impacts, respectively.
• Contributions to runoff changes were: 54.7% from the direct impact of climate change (highest in YRSB at 59.8%), 12.2% from the indirect impact of climate change, and 33.1% from human activities. The greatest influence of human activities was observed in the YRB, with contributions of 16.2% (indirect) and 42.4% (direct).

Contributions

• Provides a comprehensive assessment of both direct and indirect impacts of climate change and human activities on runoff changes, addressing a gap in existing attribution assessments that mainly focused on direct effects.
• Introduces an improved Budyko framework, integrating the elasticity coefficient method and principal component regression, to holistically analyze the complex interactions between climate, human activities, and underlying surface conditions.

Funding

• Not explicitly detailed in the provided text.

Citation

@article{Cao2026Direct,
  author = {Cao, Chengqi and Zhang, Yongyong and Zhang, Yongyong and Peng, Kun and Tang, Qi and Zhang, Yongqiang and Zhang, Yongqiang and Wang, Guoqing},
  title = {Direct and indirect impact assessments of climate changes and human activities on runoff changes in 31 source catchments of Yellow River Basin, China},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.134974},
  url = {https://doi.org/10.1016/j.jhydrol.2026.134974}
}