基于三维识别的中国西北气象干旱动态演变OA

Northwest China,one of the driest regions at its latitude globally,faces severe water security threats due to persistent drought.Understanding the spatiotemporal evolution of meteorological drought is critical for im-proving monitoring and management.Using the standardized precipitation evapotranspiration index,this study constructed a three-dimensional identification model to detect drought events from 1980 to 2019,and analyzed their evolutionary characteristics and regional disparities.Results indicate that over the past 40 years,drought ar-ea,severity,and duration increased significantly in eastern Northwest China,while maximum extent decreased,suggesting a shift from large-scale contiguous droughts to smaller,high-intensity events.Drought centroids in the east migrated northward and eastward,whereas western centroids remained stable.Seasonal heterogeneity was evident:Eastern drought severity was distributed across all seasons,with slightly higher intensity in spring and autumn;in the west,spring drought dominated overall severity.Drought migration paths showed clear regional differences,with westward movement prevailing in both areas,forming an alternating east-west axial pattern.Analysis of representative events revealed distinct migration modes and clarified drought propagation characteris-tics.These findings offer a scientific basis for enhancing early warning systems and targeted drought prevention strategies in Northwest China.