Xu et al. (2026) Characteristics of meteorological drought propagation to agricultural drought and trigger thresholds in Xinjiang, China

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-04-02
• Authors: Xuewen Xu, Fulong Chen, Fei Zhao, Run Zhang, Chaofei He
• DOI: 10.1016/j.ejrh.2026.103384

Research Groups

• College of Water Conservancy & Architectural Engineering, Shihezi University, China
• Key Laboratory of Cold and Arid Regions Eco-Hydraulic Engineering of Xinjiang Production & Construction Corps, China

Short Summary

This study quantifies the propagation characteristics and trigger thresholds from meteorological to agricultural drought in Xinjiang, China, revealing significant spatial heterogeneity and providing a quantitative basis for improved drought early warning systems and adaptation strategies.

Objective

• To clarify the propagation mechanisms from meteorological to agricultural drought in Xinjiang.
• To identify and analyze the characteristics, trends, and spatial differences of meteorological and agricultural droughts in Xinjiang over the past two decades.
• To reveal the relationships between meteorological and agricultural droughts, including propagation time, propagation probability, and trigger thresholds.

Study Configuration

• Spatial Scale: Xinjiang Uygur Autonomous Region, China (34°25′–48°10′N, 73°40′–96°18′E), covering 1.6649 million square kilometers, focusing on 14 prefectures/municipalities.
• Temporal Scale: 2000–2020 (21 years) for meteorological and soil moisture data.

Methodology and Data

• Models used:
  • Standardized Precipitation Index (SPI) and Standardized Soil Moisture Index (SSI) for drought classification.
  • Three-threshold run theory for drought event identification.
  • Pearson correlation analysis for drought response time (DRT).
  • Mann-Kendall nonparametric test for trend analysis.
  • Continuous wavelet transform for periodicity analysis.
  • Copula functions (Frank, Gumbel, Clayton) for joint distribution modeling of drought characteristics.
  • Bayesian network models for quantifying response probabilities and trigger thresholds.
  • Non-parametric kernel density estimation for marginal distributions of SPI and SSI.
  • Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) for model selection and evaluation.
• Data sources:
  • Daily observational precipitation data from 73 national basic meteorological stations (2000–2020) from the National Meteorological Information Center, processed using the Thiessen polygon method for areal precipitation.
  • Gridded soil moisture data (2000–2020) from the National Tibetan Plateau Data Center, processed for zonal averages.
  • Irrigation water use data from PANGAEA.
  • Vegetation index data for China from the Resource and Environmental Science and Data Center.
  • Spatial distribution data of soil types in China from the Resource and Environmental Science Data Platform.
  • China Flood and Drought Disaster Bulletin from the Ministry of Water Resources of the People's Republic of China.
  • Data on sown area of crops from the Bureau of Statistics of Xinjiang Uygur Autonomous Region.
  • Digital Elevation Model (DEM) data from the Geospatial Data Cloud.
  • Administrative division data from the National Geographical Information Public Service Platform.

Main Results

• The meteorological-agricultural drought matching ratio in Xinjiang ranges from 0.45 to 0.87, showing significant spatial heterogeneity.
• Meteorological droughts are, on average, 1.1 times longer and 1.3 times more intense than agricultural droughts.
• A clear north-south divergence in drought cycles exists: Northern Xinjiang experiences shorter cycles (8–16 months), while Southern Xinjiang suffers from longer, more severe cycles (32–64 months).
• For short-term meteorological droughts (1–4 months), the probability of agricultural drought response exceeds 60%. When meteorological drought duration exceeds 6 months, the response probability for agricultural drought duration of 4 months ranges from 67.71% to 99.11%.
• The dominant propagation pattern is one-to-many (L3), where a single, prolonged meteorological drought often fragments into multiple discrete agricultural drought episodes. One-to-one correspondence (L1) is observed exclusively in Changji Hui Autonomous Prefecture and Bayingolin Mongolian Autonomous Prefecture.
• Southern border regions show higher susceptibility to mild meteorological drought but greater resilience to moderate and extreme events.
• The meteorological drought threshold required to trigger agricultural drought (SSI ≤ -0.5) is generally lower (more negative SPI values) in Southern Xinjiang, ranging from -1.22 for mild agricultural drought to -3.00 for extreme agricultural drought. Hotan City and Hami City exhibit the lowest thresholds for mild-severe and extreme droughts, respectively, indicating greater resistance due to intensive irrigation.

Contributions

• Provides a systematic quantitative analysis of the entire drought propagation chain, including characteristic differences, trend evolution, probability response, and propagation thresholds, from meteorological to agricultural drought.
• Develops and applies an integrated Copula-Bayes model to move beyond traditional correlation analysis, offering a dynamic probabilistic framework for quantifying propagation likelihood and identifying precise early-warning thresholds.
• Highlights the significant spatial heterogeneity of drought propagation characteristics within an arid region, emphasizing the role of human interventions like irrigation in altering natural drought pathways.
• Offers a scientific foundation for optimizing drought early warning systems, adaptive water resources management, and agricultural drought resistance strategies in Xinjiang and other arid/semi-arid regions globally.

Funding

• National Natural Science Foundation of China (Nos. 52569004, 52169005)
• Corps Science and Technology Innovation Talents Program Project of China (2023CB008–08)
• Tianchi Talent Introduction Program of Xinjiang Uygur Autonomous Region (BT-2025-TCYC-0124)

Citation

@article{Xu2026Characteristics,
  author = {Xu, Xuewen and Chen, Fulong and Zhao, Fei and Zhang, Run and He, Chaofei},
  title = {Characteristics of meteorological drought propagation to agricultural drought and trigger thresholds in Xinjiang, China},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103384},
  url = {https://doi.org/10.1016/j.ejrh.2026.103384}
}