Li et al. (2026) Analysis of drought-flood abrupt alternation in China from 1981 to 2024

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-07
• Authors: Yifan Li, Weiwei Shao, Jiahong Liu, Jia Wang, Zhuoran Luo
• DOI: 10.1016/j.ejrh.2026.103951

Research Groups

• State Key Laboratory of Water Cycle and Water Security, China Institute of Water Resources and Hydropower Research, Beijing, 100038, China
• Key Laboratory of River Basin Digital Twinning of the Ministry of Water Resources, Beijing, 100038, China
• School of Water Resources and Hydropower Engineering, North China Electric Power University, Beijing, 102206, China

Short Summary

This study developed a daily-scale Standardized Drought-Wet Abrupt Alternation Index (SDWAI) to identify and assess Drought-Flood Abrupt Alternation (DFAA) events in mainland China. The results show that DFAA events exhibit distinct regional and seasonal characteristics at both interannual and annual scales, with a significantly increasing frequency.

Objective

• Investigate the frequency and intensity of DFAA events in mainland China using the developed daily SDWAI index.
• Analyze the spatiotemporal characteristics of DFAA events across China using observational data covering 1981–2024.
• Explore the driving effects of precipitation anomaly percentage on DFAA events.

Study Configuration

• Spatial Scale: Mainland China, divided into seven climate regions.
• Temporal Scale: Daily-scale SDWAI index, with a time span of 1981–2024.

Methodology and Data

• Models used: Standardized Drought-Wet Abrupt Alternation Index (SDWAI), modified Mann-Kendall test, Sen’s slope estimator, moving t-test.
• Data sources: Daily precipitation data from meteorological stations between 1981 and 2024, sourced from the National Meteorological Science Data Center.

Main Results

• DFAA events exhibit distinct regional and seasonal characteristics at both interannual and annual scales.
• The frequency of DFAA events is significantly increasing over time.
• The SDWAI index can accurately identify sudden extreme precipitation drought events in the short term.
• The study proposes a national threshold of ±0.6 for application across different arid and humid regions.

Contributions

• This study provides a scientific basis for an in-depth understanding of the national characteristics of compound drought and flood events.
• The developed daily SDWAI index can accurately identify DFAA events, providing valuable information for disaster prevention and mitigation capabilities.

Funding

• This research was funded by the State Key Laboratory of Water Cycle and Water Security, China Institute of Water Resources and Hydropower Research.

Citation

@article{Li2026Analysis,
  author = {Li, Yifan and Shao, Weiwei and Liu, Jiahong and Wang, Jia and Luo, Zhuoran},
  title = {Analysis of drought-flood abrupt alternation in China from 1981 to 2024},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103951},
  url = {https://doi.org/10.1016/j.ejrh.2026.103951}
}