【摘要】 在全球气候变化背景下，中国干旱化趋势加剧，对水资源与生态系统构成严峻威胁。然而，干旱演变过程存在显著的时空异质性和驱动机制不确定性。本研究基于GSWP3、CRU＿TS和Terra Climate三套多源气象数据，分析了1951—2024年中国干旱指数(Aridity Index,AI)及干旱区面积的时空变化特征。结果表明:全国旱地面积显著扩大，干旱指数整体下降，西北、华北和东北地区干旱化尤为突出。大气蒸发需求(Atmospheric Evaporative Demand,AED)的增强是干旱加剧的主要驱动力，其对干旱指数下降的相对贡献在多数区域超过70%，在旱地扩张中的贡献率分别为77.5%、97%和99.1%。相比之下，降水变化影响较为有限，仅在局部地区发挥缓解作用。研究揭示了中国干旱演变的复杂性与空间异质性，为干旱风险评估及水资源适应性管理提供了科学依据。更多还原

【Abstract】 Drought in China has intensified with ongoing climate change,posing growing risks to water security and ecosystem stability. Nevertheless,the evolution of drought exhibits pronounced spatial-temporal heterogeneity and uncertainty in its driving mechanisms. Using three independent climate datasets( GSWP3,CRU＿TS,and TerraClimate),this work systematically examined the spatiotemporal variations of the aridity index( AI) and dryland expansion in China from 1951 to 2024. Results indicated that a significant expanded of dryland areas and an overall declined in AI,with accelerating drought severity in Northwest,North,and Northeast China. Attribution analysis highlighted rising atmospheric evaporative demand( AED) as the dominant driver,contributing more than 70% to AI reduction in most regions,and accounting for 77. 5%,97%,and 99. 1% of dryland expansion in the three datasets,respectively. In contrast,precipitation changes exerted weaker and regionally limited effects,sometimes alleviating drought locally. These findings underscored the complexity and spatial heterogeneity of drought evolution in China,providing a scientific basis for drought risk assessment and adaptive water resource management.更多还原