Wang et al. (2025) Upper bound of pre-fill volume in cascade reservoirs considering forecast rainfall and its uncertainty

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-11-22
• Authors: Qianning Wang, Wei Ding, Min Li, Yueyang Yu, Jinnan Zhang, Yong Peng
• DOI: 10.1016/j.jhydrol.2025.134639

Research Groups

• School of Hydraulic Engineering, Dalian University of Technology, Dalian, China
• Dalian Zhishui Huicheng Technology Co., Ltd., Dalian, China
• Ningbo Research Institute, Dalian University of Technology, Ningbo, China

Short Summary

This study developed a risk-controlled framework to determine the upper bound of pre-fill volume (UBFV) for cascade reservoirs, explicitly linking forecast uncertainty to flood risk through probabilistic constraints to enhance floodwater utilization without increasing flood risk. It quantified UBFV for reservoir clusters and analyzed the impact of forecast uncertainty across spatial rainfall distribution, forecast lead time, and allowable flood high water level.

Objective

• To establish a risk-controlled framework for determining the upper bound of pre-fill volume (UBFV) in cascade reservoirs, ensuring no additional flood risk is introduced.
• To quantitatively assess how forecast uncertainties influence flood risks and to derive UBFV for reservoir clusters under risk-neutral conditions.
• To quantify inter-reservoir UBFV relationships within cascades and analyze the impacts of forecast uncertainty across spatial rainfall distribution, forecast lead time, and allowable flood high water level.

Study Configuration

• Spatial Scale: Jinxia Reservoir Group and the Three Gorges Cascade Reservoir System (China).
• Temporal Scale: 1–7-day rainfall forecasts; analysis of forecast periods (e.g., 3-5 days, 6-7 days).

Methodology and Data

• Models used: A risk-controlled framework incorporating probabilistic constraints to explicitly link forecast uncertainty and flood risk.
• Data sources: Forecast rainfall (1-7 day forecasts).

Main Results

• The maximum UBFV is determined to be 5.2 × 10⁹ m³ for the Jinxia system and 5.1 × 10⁹ m³ for the Three Gorges system, utilizing 1–7-day rainfall forecasts.
• UBFV initially increases and then decreases with longer forecast periods, reaching its maximum value at 6–7 days in Jinxia and 3–5 days in Three Gorges. Higher forecast accuracy reduces UBFV.
• A higher allowable flood high water level leads to a higher UBFV of the reservoir.

Contributions

• Established a systematic, risk-controlled framework to quantitatively assess the influence of forecast uncertainties on flood risks and determine the upper bound of pre-fill volume (UBFV) for cascade reservoirs.
• Explicitly linked forecast uncertainty to flood risk through probabilistic constraints, ensuring no additional flood risk is introduced while enhancing floodwater utilization.
• Quantified inter-reservoir UBFV relationships within cascades and comprehensively analyzed the impacts of forecast uncertainty across spatial rainfall distribution, forecast lead time, and allowable flood high water level.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{Wang2025Upper,
  author = {Wang, Qianning and Ding, Wei and Li, Min and Yu, Yueyang and Zhang, Jinnan and Peng, Yong},
  title = {Upper bound of pre-fill volume in cascade reservoirs considering forecast rainfall and its uncertainty},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134639},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134639}
}