Mechanisms of meteorological drought propagation to agricultural drought in China: insights from causality chain

Abstract

Abstract Previous studies have overlooked the nonlinear dependency of drought propagation, limiting our understanding of its mechanisms. By establishing a causality chain, this study identifies the nonlinear propagation pathways of meteorological drought to agricultural drought across different climatic zones in China from 2000 to 2018 and elucidates the driving factors contributing to the divergences in propagation characteristics among these regions. The findings indicate a linear drought propagation time (DPT) of approximately two months, occurring around 25 times on average, demonstrating peer-to-peer drought propagation overall. Temperature and surface air pressure emerge as the primary driving factors, accounting for over 50% of the observed drought propagation. The interplay between precipitation (P), soil moisture (SM), and potential evapotranspiration (PET) explains the disparities in nonlinear propagation across different regions. Increased area wetness enhances nonlinear drought propagation, while linear propagation decreases. This study offers crucial insights for improving drought management and agricultural water resource strategies.