Lv et al. (2025) Attributing changes in evapotranspiration and runoff across the continental U.S. using the Budyko hypothesis combined with the Shuttleworth-Wallace model

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-12-22
• Authors: Ran Lv, Shanlei Sun, Zaoying Bi, Yi Hui Liu, Qianrong Ma, Yongjian Ren, Lingna Wei, Yang Zhou, Botao Zhou
• DOI: 10.1016/j.jhydrol.2025.134831

Research Groups

• State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster, Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, China
• School of Civil and Environmental Engineering, University of New South Wales, Sydney, Australia
• College of Physical Science and Technology, Yangzhou University, Yangzhou, China
• Hubei Meteorological Service Center, Wuhan, China
• School of Hydrology and Water Resources, Nanjing University of Information Science and Technology, Nanjing, China

Short Summary

This study developed a new framework combining the Budyko hypothesis with the Shuttleworth-Wallace model to explicitly attribute changes in evapotranspiration and runoff to climate, vegetation, and land use/cover change across 732 catchments in the continental U.S., revealing precipitation as the dominant factor for ET and runoff changes in most catchments, but highlighting the significant influence of vegetation and land use/cover changes.

Objective

• To quantify the contributions of climate, vegetation (e.g., leaf area index and physiological effects of CO2), land use/cover change (LUCC), and other land properties to changes in evapotranspiration (ET) and runoff (R) by combining the Budyko hypothesis with the Shuttleworth-Wallace (SW) potential evapotranspiration (PET) model.

Study Configuration

• Spatial Scale: 732 catchments across the continental U.S.
• Temporal Scale: Two decades (2000s and 2010s), relative to a baseline period from 1991 to 2000.

Methodology and Data

• Models used: Budyko hypothesis combined with the Shuttleworth-Wallace (SW) potential evapotranspiration (PET) model; Food and Agriculture Organization of the United Nations-56 Penman-Monteith model (for comparison).
• Data sources: The study explicitly incorporates variables such as precipitation (P), non-precipitation climatic variables (non-PCV), leaf area index (LAI), physiological effects of CO2, and land use/cover change (LUCC) into the attribution framework. Specific data sources (e.g., satellite products, reanalysis datasets) for these variables are not detailed in the provided text.

Main Results

• Evapotranspiration (ET) increased in over 50% of the catchments during both the 2000s and 2010s.
• Runoff (R) decreased in 69% of catchments in the 2000s and 46% in the 2010s.
• Precipitation (P) was the dominant factor for ET changes in over 45% of catchments during both periods.
• Non-precipitation climatic variables (non-PCV) affected more than 15% of catchments for ET changes.
• The Budyko parameter 'n' was the dominant factor for ET changes in approximately 35% of catchments.
• For runoff (R) changes, P, non-PCV, and parameter 'n' dominated in about 60%, 10%, and 30% of catchments, respectively.
• Approximately 45% of catchments experienced shifts in the dominant factor affecting ET or R changes from the 2000s to the 2010s, with over 20% transitioning primarily between P and parameter 'n'.
• Comparing the Budyko-SW framework with the FAO-56 Penman-Monteith model revealed different dominant factors for ET or R changes in over 7% of catchments, indicating that overlooking the effects of CO2, LAI, and LUCC significantly influences attribution.

Contributions

• Developed an integrated framework that combines the Budyko hypothesis with the Shuttleworth-Wallace model, allowing for explicit incorporation and attribution of vegetation (LAI, CO2 physiological effects) and land use/cover change impacts on ET and R.
• Provided a comprehensive attribution analysis of ET and R changes across the continental U.S., distinguishing the roles of climate, vegetation, and LUCC.
• Demonstrated that neglecting vegetation and LUCC effects can lead to significant differences in the attribution of hydrological changes, offering a valuable reference for future studies in other regions.

Funding

Not explicitly mentioned in the provided text.

Citation

@article{Lv2025Attributing,
  author = {Lv, Ran and Sun, Shanlei and Bi, Zaoying and Liu, Yi Hui and Ma, Qianrong and Ren, Yongjian and Wei, Lingna and Zhou, Yang and Zhou, Botao},
  title = {Attributing changes in evapotranspiration and runoff across the continental U.S. using the Budyko hypothesis combined with the Shuttleworth-Wallace model},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134831},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134831}
}