Gao et al. (2026) Remote sensing-based water balance model to estimate the actual ET in Loess Plateau

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-09
• Authors: Xuerui Gao, Xiuping Li, Junhao Zhao, Ai Wang, Jiajun Chen, Shuyu Zhang
• DOI: 10.1016/j.ejrh.2026.103964

Research Groups

• Institute of Soil and Water Conservation, Northwest A&F University
• College of Soil and Water Conservation Science and Engineering, Northwest A&F University
• College of Water Resources and Architectural Engineering, Northwest A&F University

Short Summary

This study developed a remote sensing-based water balance assessment tool (RWBAT) to estimate actual evapotranspiration (AET) over the Loess Plateau. The model was calibrated and validated using reference ET products and independent field observations.

Objective

• Develop a regional water balance model that couples grid-scale vertical soil water movement with sub-basin-scale runoff generation and routing.
• Calibrate and validate the model using remote sensing ET reference product and independent field observations.
• Reveal the long-term spatiotemporal changes in AET over the Loess Plateau during 1991–2020.

Study Configuration

• Spatial Scale: The study area is the Loess Plateau, China, with a spatial resolution of approximately 10 km.
• Temporal Scale: The study period is from 1991 to 2020.

Methodology and Data

• Models used: RWBAT model, which integrates remote sensing data with physically based and conceptual hydrological algorithms for AET estimation and water balance assessment.
• Data sources: Meteorological data (China meteorological forcing dataset), soil data (China Soil Data Map), vegetation data (MODIS MYD13Q1 dataset and PKU GIMMS NDVI), and ERA-Interim soil moisture data.

Main Results

• The RWBAT model was calibrated and validated using reference ET products and independent field observations.
• The average annual AET over the Loess Plateau during 1991–2020 ranged from 297.53 to 421.33 mm, with a mean value of 357.73 mm.
• An abrupt change in AET occurred around 2009, which may be related to the delayed hydrological response of vegetation restoration and climate variability.

Contributions

• This study provides an integrated water balance framework for analyzing regional hydrological processes over the Loess Plateau.
• The RWBAT model can provide continuous daily simulations over a long period and couples AET estimation with canopy interception, soil water change, surface runoff, lateral flow, groundwater recharge, and sub-basin routing.

Funding

• This study was funded by the National Natural Science Foundation of China (Grant No. 51979219).

Citation

@article{Gao2026Remote,
  author = {Gao, Xuerui and Li, Xiuping and Zhao, Junhao and Wang, Ai and Chen, Jiajun and Zhang, Shuyu},
  title = {Remote sensing-based water balance model to estimate the actual ET in Loess Plateau},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103964},
  url = {https://doi.org/10.1016/j.ejrh.2026.103964}
}