Zhao et al. (2025) The propagation mechanism of meteorological drought to agricultural drought in Southwest China

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2025
• Date: 2025-12-20
• Authors: Yang Zhao, Weiguang Wang
• DOI: 10.1007/s00704-025-05968-0

Research Groups

• Hydrology and Water Resources Center of Henan Province, Zhengzhou, China
• National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, China
• College of Hydrology and Water Resources, Hohai University, Nanjing, China
• Yangtze Institute for Conservation and Development, Hohai University, Nanjing, China

Short Summary

This study investigates the propagation mechanism of meteorological drought to agricultural drought in Southwest China, differentiating between karst and non-karst areas, by proposing novel drought propagation indices (DSTP, DVP) and analyzing propagation rates, types, and driving mechanisms. The findings reveal distinct propagation characteristics and influencing factors across these regions, highlighting the vulnerability of karst areas.

Objective

• To clarify the propagation mechanism of meteorological drought to agricultural drought in Southwest China, specifically by proposing new drought propagation indices (Drought Propagation Index of Trend of Severity - DSTP, and Drought Volatility Propagation Index - DVP) and analyzing the propagation rates, types, and driving mechanisms of meteorological drought characteristics to agricultural drought characteristics in both karst and non-karst areas.

Study Configuration

• Spatial Scale: Southwest China (Yunnan Province, Guangxi Zhuang Autonomous Region, Guizhou Province, Sichuan Province, and Chongqing City), covering approximately 1.37 x 10^6 square kilometers, with a specific focus on differentiating between karst and non-karst areas.
• Temporal Scale: January 1, 1980, to December 31, 2018 (39 years).

Methodology and Data

• Models used:
  • Standardized Precipitation Index (SPI) for meteorological drought.
  • Standardized Soil Moisture Index (SSMI) for agricultural drought.
  • Run theory method for identifying drought events.
  • Copula function (Clayton Copula) for determining drought propagation time.
  • Drought Duration Propagation Index (DDP).
  • Drought Intensity Propagation Index (DIP).
  • Drought Propagation Index of Trend of Severity (DSTP) (proposed in this study).
  • Drought Volatility Propagation Index (DVP) (proposed in this study).
  • Penman-Monteith equation for potential evapotranspiration calculation.
  • Kolmogorov Smirnov test (K-S test) for normality.
  • Kernel density estimation for cumulative distribution probability (if not normal).
• Data sources:
  • Precipitation, temperature, wind speed, air pressure, ground level shortwave radiation, ground level longwave radiation, air humidity: China Meteorological Forcing Dataset (CMFD).
  • Surface (0-10 cm) soil moisture: GLDAS-2.0 Noah (1979-2010) and GLDAS-2.1 Noah (2011-2018) after bias correction.
  • Actual evapotranspiration: Global Land Evaporation Amsterdam Model (GLEAM) v3.8a.
  • NDVI: PKU GIMMS NDVI dataset.
  • DEM and slope data: National Tibetan Plateau Data Center.
  • Lithologic data: Global lithologic map.

Main Results

• The average propagation time from meteorological drought to agricultural drought in Southwest China is 125 days, with karst areas averaging 120 days and non-karst areas averaging 130 days.
• The average Drought Duration Propagation Index (DDP) is 0.89, with non-karst areas (0.90) showing a slightly higher value than karst areas (0.88).
• The average Drought Intensity Propagation Index (DIP) is 1.50, with karst areas (1.52) showing a slightly higher value than non-karst areas (1.48).
• The average Drought Propagation Index of Trend of Severity (DSTP) is 1.58, with karst areas (1.60) showing a slightly higher value than non-karst areas (1.56).
• The average Drought Volatility Propagation Index (DVP) is 1.20 across all regions.
• For drought duration and volatility propagation, the "peer-to-peer" type is most prevalent in Southwest China (25.32% for DDP, 31.08% for DVP), karst areas, and non-karst areas.
• For drought intensity and the growth trend of drought severity propagation, the "extra strong" type is most prevalent in Southwest China (54.82% for DIP, 56.79% for DSTP), karst areas (42.00% for DIP, 42.97% for DSTP), and non-karst areas. This indicates that agricultural drought intensity and severity trend often increase more significantly than meteorological drought in these regions, particularly in karst areas.
• DDP is most strongly correlated with average annual precipitation, while DIP, DSTP, and DVP show the strongest correlation with altitude across Southwest China.
• The correlation between DIP, DSTP, DVP, and average annual potential evapotranspiration is stronger in karst areas than in non-karst areas, whereas the correlation between DDP and average annual potential evapotranspiration is weaker in karst areas.
• DIP and DSTP exhibit the strongest correlation with meteorological drought severity in all study areas.

Contributions

• Proposed two novel drought propagation indices: Drought Propagation Index of Trend of Severity (DSTP) and Drought Volatility Propagation Index (DVP), enhancing the characterization of drought propagation.
• Integrated drought propagation time into the calculation of DDP, DIP, DSTP, and DVP, providing a more comprehensive understanding of the propagation process.
• Revealed distinct differences in the propagation mechanisms of meteorological drought to agricultural drought between karst and non-karst areas in Southwest China, addressing a gap in existing literature.
• Provided a theoretical basis and technical support for drought research, prevention, and control strategies, particularly relevant for managing rocky desertification in karst regions.

Funding

• National Natural Science Foundation of China (grant number 52479010).

Citation

@article{Zhao2025propagation,
  author = {Zhao, Yang and Wang, Weiguang},
  title = {The propagation mechanism of meteorological drought to agricultural drought in Southwest China},
  journal = {Theoretical and Applied Climatology},
  year = {2025},
  doi = {10.1007/s00704-025-05968-0},
  url = {https://doi.org/10.1007/s00704-025-05968-0}
}