Integrated Analysis and Prediction of Drought in the Endorheic Basins of China

ABSTRACT The Endorheic Basins of China (EBC), covering 39% of the national territory, are ecologically fragile and highly sensitive to climate variability, making drought a critical concern for regional water resources management and ecological security. Unlike most studies that focus solely on Northwest China, the EBC also encompass the northern Tibetan Plateau and the central‐eastern Inner Mongolia Plateau, featuring more diverse and complex hydroclimatic conditions. Nevertheless, basin‐wide drought research remains limited, often overlooking smaller zones within the EBC, particularly in relation to compound and extreme droughts. From both panoramic and subregional perspectives, this study systematically analyzes trends of wetting and drying and subregional compound droughts at non‐event scales, as well as the characteristics of drought and extreme drought events at event scales, using China Meteorological Forcing Data for the historical period (1960–2024) and CMIP6 for the future period (2025–2100). The results indicate: (1) Six subregions are identified based on SPEI, with the dry‐wet division predominantly governed by topography, while the boundaries progressively shift in response to enhanced radiative forcing. (2) The study area exhibits a pronounced drying trend that intensifies with increasing radiative forcing, with relatively low‐altitude areas remaining persistently arid while high‐altitude mountainous areas tend to become relatively wetter. (3) The frequency and intensity of regional compound droughts are projected to weaken in the future, but the risk of severe compound droughts remains higher than historical levels in most scenarios. (4) With increasing radiative forcing, droughts and extreme events occur less frequently, last longer, and show stronger spatial differentiation. (5) Atlantic, tropical Pacific, and Indian Ocean SST anomalies, together with elevation, jointly regulate the spatiotemporal patterns of drought.