Zhang et al. (2026) Revealing hidden structural regimes in fluvial stage–discharge relationships using time-series imaging

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-09-01
• Authors: Jiarui Zhang, Shenliang Chen, Yaoshen Fan, Hongyu Ji, Taihuan Hu, Jianbin Chen
• DOI: 10.1016/j.jhydrol.2026.136487

Research Groups

• State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
• Key Laboratory of Yellow River, the Ministry of Water Resources, Yellow River Institute of Hydraulic Research, Zhengzhou 450003, China
• National Marine Environmental Monitoring Center, Ministry of Ecology and Environment, Dalian 116023, China
• The Yellow River Delta Sustainable Development Institute of Shandong Province, Dongying 257000, China

Short Summary

This study reveals that annual stage–discharge dynamics in the lower Yellow River exhibit a limited set of identifiable structural regimes, rather than varying as a smooth continuum. A physics-guided time-series imaging framework is developed to classify these regimes.

Objective

• Investigate the long-term variability of stage–discharge relationships in alluvial rivers and determine whether their nonstationarity is truly unstructured or organized into recurrent structural regimes.

Study Configuration

• Spatial Scale: Lower Yellow River, China
• Temporal Scale: 75 years (daily records)

Methodology and Data

• Models used: Physics-guided time-series imaging framework integrating Markov Transition Field (MTF) encoding, dual-branch convolutional representation learning, derivative-based physics-guidance encoding, and hierarchical clustering.
• Data sources: Daily stage and discharge records from the Lijin hydrological station.

Main Results

• Annual stage–discharge dynamics recur as a limited set of identifiable structural regimes.
• Relative to non-physics-guided frameworks, the physics-guided framework reorganizes interannual similarity into less fragmented and more hydraulically consistent structural groups.
• Distinctions among regimes manifest primarily in state persistence, cross-seasonal reconnection, and hysteretic coupling between stage and discharge.

Contributions

• This study provides a new understanding of the organization of nonstationarity in fluvial systems, which may support adaptive management and structural monitoring in regulated river systems.
• The physics-guided time-series imaging framework developed in this study offers a potential transferable methodological paradigm for comparable fluvial systems worldwide.

Funding

• This research was funded by the State Key Laboratory of Estuarine and Coastal Research (Grant No. SKLEC2023001) and the National Natural Science Foundation of China (Grant Nos. 42161160517 and 42061160701).

Citation

@article{Zhang2026Revealing,
  author = {Zhang, Jiarui and Chen, Shenliang and Fan, Yaoshen and Ji, Hongyu and Hu, Taihuan and Chen, Jianbin},
  title = {Revealing hidden structural regimes in fluvial stage–discharge relationships using time-series imaging},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136487},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136487}
}