Xu et al. (2026) Nonstationary flood frequency analysis and drivers in the middle-lower Yangtze River, China

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-05
• Authors: Chen Xu, Zhouhui Huang, Anqi Wang, Yang Xiao, Taotao Zhang, Hua Qin, Zihao Guo
• DOI: 10.1016/j.ejrh.2026.103930

Research Groups

• School of Geography Science and Geomatics Engineering, Suzhou University of Science and Technology
• College of Water Conservancy and Hydropower Engineering, Hohai University
• College of Jiyang, Zhejiang A&F University
• Three Gorges New Waterway (Hubei) Co., Ltd

Short Summary

This study investigates nonstationary flood frequency and climatic and anthropogenic drivers in the middle-lower Yangtze River Basin, China. The analysis reveals pronounced spatial heterogeneity along the river continuum, with statistically significant nonstationarity identified at Yichang, Luoshan, and Hankou Stations.

Objective

• Investigate nonstationary flood frequency behavior and its associated drivers in the middle-lower Yangtze River Basin.
• Examine how antecedent precipitation, flood-season temperature, large-scale climate modes, and reservoir regulation are associated with different parts of the flood quantiles.
• Determine how the relative importance of reservoir regulation and climatic forcing varies along the river continuum.

Study Configuration

• Spatial Scale: The study focuses on the middle-lower Yangtze River Basin in China, represented by four hydrological stations: Yichang, Luoshan, Hankou, and Datong.
• Temporal Scale: The analysis covers a period of 1960-2022.

Methodology and Data

• Models used: Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used to model annual flood peaks and 30-day flood volumes.
• Data sources:
  • Hydrological observations from the Yangtze River Hydrology and Water Resources Survey Bureau.
  • Meteorological variables from the National Tibetan Plateau Data Center.
  • Large-scale climate indices from the National Oceanic and Atmospheric Administration and relevant climate-index data providers.

Main Results

• Flood-frequency nonstationarity exhibits pronounced spatial heterogeneity along the middle-lower Yangtze River.
• Statistically significant nonstationarity is identified at Yichang, Luoshan, and Hankou Stations, whereas Datong Station shows neither a significant monotonic trend nor a significant change point during the study period.
• An empirically selected 27–28-day antecedent precipitation window, flood-season maximum temperature (TMAX), the modified reservoir index (MRI), and El Ni˜no–Southern Oscillation (ENSO) improve the representation of nonstationary flood-frequency distributions.

Contributions

• This study provides new hydrological insight into the spatially varying and quantile-dependent responses of flood-frequency nonstationarity in a large regulated river system.
• The analysis highlights the importance of considering both climatic and anthropogenic drivers in understanding flood frequency behavior.

Funding

• This research was funded by projects, programs, and reference codes not specified in the provided text.

Citation

@article{Xu2026Nonstationary,
  author = {Xu, Chen and Huang, Zhouhui and Wang, Anqi and Xiao, Yang and Zhang, Taotao and Qin, Hua and Guo, Zihao},
  title = {Nonstationary flood frequency analysis and drivers in the middle-lower Yangtze River, China},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103930},
  url = {https://doi.org/10.1016/j.ejrh.2026.103930}
}