Xue et al. (2025) Development and assessment of a C-vine copula-based composite drought index coupling multiple hydrological cycle variables in the North China Plain

Identification

• Journal: Journal of Water and Climate Change
• Year: 2025
• Date: 2025-12-01
• Authors: Jianwen Xue, Qiang Zhao, Zhicheng Zhong, Jianing Wang, Feng Lin, Ping Yang
• DOI: 10.2166/wcc.2025.195

Research Groups

• School of Water Conservancy and Environment, University of Jinan, China
• Culture and Tourism College, University of Jinan, China
• Institute of Desert Meteorology, China Meteorological Administration, China

Short Summary

This study developed two C-vine copula-based composite drought indices (CDI-P and CDI-R) by coupling multiple hydrological variables to comprehensively monitor drought in the North China Plain. The CDIs effectively capture drought events with low false alarm and omission rates, revealing increasing trends in drought duration, intensity, and severity since 2000.

Objective

• To develop and assess C-vine copula-based composite drought indices (CDIs) by coupling precipitation, potential evapotranspiration, soil moisture, and runoff in the North China Plain.
• To evaluate the effectiveness, monitoring capabilities, and response features of the CDIs compared to traditional drought indices.
• To analyze the spatiotemporal and evolutionary patterns of composite drought events using a 3D identification method.

Study Configuration

• Spatial Scale: North China Plain (32°N–40°N, 114°E–121°E) at approximately 4 km spatial resolution.
• Temporal Scale: 1959–2023 (65 years) with monthly data, analyzed at 3-month and 6-month timescales.

Methodology and Data

• Models used: C-vine copula modeling framework (using Clayton, Gumbel, Frank, Gaussian bivariate copulas), Gringorten method for empirical joint probability, Mann–Kendall (MK) trend test, linear regression, Pearson correlation analysis, Kolmogorov–Smirnov (K–S) test.
• Data sources: TerraClimate global high-resolution dataset (precipitation, potential evapotranspiration, soil moisture, runoff), China Flood and Drought Disaster Prevention Bulletin (historical drought records).

Main Results

• Two composite drought indices (CDI-P and CDI-R) were developed using a C-vine copula model, with precipitation (P) and runoff (R) as central variables, respectively.
• The CDIs effectively capture drought events, showing strong correlations with traditional drought indices (e.g., CDI-P with SPI/SPEI: 0.65/0.64; CDI-R with SRI: 0.65) and maintaining low false alarm and omission rates.
• CDIs exhibit lower sensitivity and specificity for agricultural drought compared to meteorological and hydrological droughts.
• Optimal drought patch area thresholds were determined as 6% for CDI-P and 5.5% for CDI-R.
• Composite droughts show higher intensity (generally exceeding 1.0) and a lagged onset relative to meteorological droughts, but an earlier recovery than agricultural droughts.
• Since 2000, the North China Plain has experienced increasing trends in drought duration, intensity, and severity, with drought migration predominantly along the northeast–southwest axis.
• Regional precipitation showed a decreasing trend (Mann–Kendall Z = –1.50), while potential evapotranspiration significantly increased (Z = 5.84), and soil moisture (Z = –3.67) and runoff (Z = –2.39) significantly decreased.

Contributions

• Development of novel C-vine copula-based composite drought indices (CDI-P and CDI-R) that integrate multiple hydrological cycle variables (precipitation, potential evapotranspiration, soil moisture, runoff) to capture complex, nonlinear drought dependencies.
• Improved capabilities in revealing interrelationships among various drought processes and capturing their compound impacts compared to traditional single-variable indices.
• Application of a 3D drought identification method to systematically analyze the spatiotemporal evolution, migration patterns, and characteristics of composite drought events, providing richer information for dynamic monitoring.
• Provision of a scientific basis for regional drought risk assessment and mitigation planning in the North China Plain by highlighting the integrated regulatory role of hydrological cycle variables in drought evolution.

Funding

• Shandong Provincial Natural Science Foundation (No. ZR2024QD207, ZR2024ME171)
• China Postdoctoral Science Foundation (No. 2025MD774146)
• Special Funds for Basic Scientific Research Business Expenses at Central-level Public Welfare Scientific Research Institutes (No. IDM2024001)
• New Talent Research Project University of Jinan (No. XJ2024011901)
• National Natural Science Foundation of China (No. 41471160)

Citation

@article{Xue2025Development,
  author = {Xue, Jianwen and Zhao, Qiang and Zhong, Zhicheng and Wang, Jianing and Lin, Feng and Yang, Ping},
  title = {Development and assessment of a C-vine copula-based composite drought index coupling multiple hydrological cycle variables in the North China Plain},
  journal = {Journal of Water and Climate Change},
  year = {2025},
  doi = {10.2166/wcc.2025.195},
  url = {https://doi.org/10.2166/wcc.2025.195}
}