Processes and driving mechanisms of drought propagation in Central Asia: A coupled perspective of meteorological, surface water, agricultural, and groundwater drought

Central Asia A comprehensive framework was used to in this study investigate the propagation processes and driving mechanisms of meteorological drought (MD), surface water drought (SD), agricultural drought (AD), and groundwater drought (GD) in Central Asia during 2003–2023. Run theory was leveraged to detect drought events, while the center of gravity model was employed to analyze their migration characteristics at different scales. Furthermore, maximal correlation analysis and wavelet analyses were utilized to quantify propagation processes. The Geodetector and XGBoost-SHAP methods were integrated to identify key drivers. In recent years, MD, AD, and GD have intensified, while SD has slightly eased. Drought centers have been concentrated in the heart of Central Asia. The propagation time from MD to SD has been relatively short (1.43 months), followed by AD (3.32 months), while propagation to GD was notably longer (14.91–18.63 months). The propagation of MD to SD and AD was the most pronounced in arid regions, which are regional characteristics regulated by mountain precipitation and snowmelt. Moreover, temperature, elevation, and precipitation were the main drivers of propagation from MD to SD, MD to AD, and from SD to GD. Human activities have a significant influence on drought propagation processes via crop structure, irrigation practices, and groundwater extraction. Our study results provide novel insights into the dynamics and mechanisms of drought propagation in Central Asia brought about by global changes. • Meteorological, agricultural, and groundwater droughts have worsened. • Meteorological drought propagates fastest to surface water drought. • Human activities weaken the link between groundwater drought and other types. • Quantified the contribution of driving factors to drought propagation.