Sun et al. (2026) Monitoring monthly water storage variation of the Three Gorges Reservoir using SWOT observations

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-06-29
• Authors: Hui Li, Yonggui Wang
• DOI: 10.1016/j.jhydrol.2026.135952

Research Groups

• Hubei Key Laboratory of Regional Ecology and Environmental Change
• School of Geography and Information Engineering, China University of Geosciences

Short Summary

This study presents a novel Water Volume plus Compensation Volume (WV + CV) framework for estimating reservoir storage in elongated riverine reservoirs, leveraging SWOT mission observations to capture two-dimensional water surface structure.

Objective

• Investigate the feasibility of using wide-swath SWOT observations to monitor monthly water storage variation in the Three Gorges Reservoir.
• Develop a novel WV + CV method that accounts for non-uniform water surface morphology in elongated riverine reservoirs.

Study Configuration

• Spatial Scale: The study focuses on the Three Gorges Reservoir, with a spatial scale of approximately 660 km in length and 1-2 km in width.
• Temporal Scale: The study period spans from August 2023 to August 2025, covering two full years of seasonal transitions.

Methodology and Data

• Models used: Water Volume plus Compensation Volume (WV + CV) framework
• Data sources: Surface Water and Ocean Topography (SWOT) mission observations

Main Results

• The proposed WV + CV method demonstrates strong agreement with reference estimates (R2 = 0.970; RMSE = 0.929 km3) in estimating reservoir storage variations.
• Conventional trapezoidal and area-elevation-volume approaches systematically underestimate storage variations under intensified longitudinal gradients.

Contributions

• This study provides a scalable framework for monitoring storage dynamics in elongated riverine reservoirs using SWOT observations.
• The WV + CV method offers a novel approach to account for non-uniform water surface morphology, reducing systematic volumetric biases caused by pronounced longitudinal water level gradients.

Funding

• This research was funded by the National Natural Science Foundation of China (Grant No. 42171021) and the Hubei Provincial Key Laboratory of Regional Ecology and Environmental Change (Grant No. 2021KF01).

Citation

@article{Sun2026Monitoring,
  author = {Sun, Qiye and Li, Hui and Wang, Yonggui},
  title = {Monitoring monthly water storage variation of the Three Gorges Reservoir using SWOT observations},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.135952},
  url = {https://doi.org/10.1016/j.jhydrol.2026.135952}
}