Characterization of agricultural drought propagation over China based on bivariate probabilistic quantification

Agricultural drought has become a serious threat to the world food security and sustainable development. Although various characteristics have been investigated for agricultural drought assessment and early warning, the propagation of meteorological drought to agricultural drought is less than clear. This study investigated the spatiotemporal variations of characteristics of the propagation from meteorological drought to agricultural drought over China during the period of 1953-2012. The Standardized Precipitation Index (SPI) and the Standardized Soil moisture Index (SSI) were used to characterize meteorological drought and agricultural drought, respectively. The SSI-1 and SPI-m (1-12) were chosen as drought propagation series by correlation analysis to evaluate the correlation and propagation time between these two droughts. The probability of propagation in different regions of China was quantified using copula-based models. Results indicated that the strongest and the weakest correlations between meteorological drought and agricultural drought were found in summer (0.8-0.9) and in winter (0.5-0.8), respectively, while the propagation time increased from 1 to 2 months in summer to 2-7 months in the next spring. Spatially, correlation and propagation sensitivity between meteorological drought and agricultural drought were greater in humid areas than in other climatic zones. Further, the probability of agricultural drought occurrence was found to synchronously increase with the severity of meteorological drought. This study will help improve drought warning and forecasting systems.

Automated summary

This study investigated the spatiotemporal variations of the propagation characteristics from meteorological drought to agricultural drought in China. Results show that the strongest correlation between meteorological and agricultural drought was in summer, with shorter propagation time, while the correlation and propagation sensitivity were greater in humid areas.