伊犁河流域多时间尺度气象干旱时空特征OA

The Ili River,a key transboundary river linking Xinjiang,China,and Kazakhstan,has experienced in-creasingly severe droughts.Based on ERA5-Land reanalysis data(1980-2023)and using the standardized pre-cipitation evapotranspiration index(SPEI)as the evaluation metric,the multi-timescale spatiotemporal character-istics of meteorological drought in the Ili River Basin were systematically analyzed using the Theil-Sen slope,run theory,and probability distribution functions.Results indicate that(1)From 1980 to 2023,the SPEI exhibit-ed a significant declining trend in spring,summer,autumn,and annually(P<0.05),with a quasi-periodic oscilla-tion of～7 and～13 years at the annual scale.(2)Over the past 44 years,drought frequency increased,and drought severity significantly intensified(P<0.05)at monthly,seasonal,and annual scales.(3)Drought conditions were most severe from 2020 to 2023,with drought frequency and intensity reaching their highest values in 44 years.(4)Drought duration was strongly positively correlated with severity,with similar spatial patterns of their return periods and consistent joint and cooccurrence probabilities.(5)Spatially,areas around Lake Balkhash and parts of the Ili River Basin in China were identified as drought hotspots,exhibiting pronounced drying trends and fre-quent extreme events;thus,strengthening drought monitoring and early warning systems in these regions is essen-tial.These findings provide a scientific basis for drought risk prevention and adaptive management in the Ili Riv-er Basin.