近40a内蒙古冬旱时空演变特征OA北大核心CSTPCD

Winter drought is a main factor hindering winter livestock production in Inner Mongolia.Thus,quanti-tative characterization of its spatiotemporal changes and development patterns is of great significance for disaster prevention and reduction and for ensuring the healthy development of agriculture and animal husbandry.Using ERA5-Land reanalysis meteorological data from the winter of 1980 to 2021(October to March of the following year),the standardized precipitation evapotranspiration index(SPEI)was calculated at monthly and semi-annual scales.Trend analysis,spatiotemporal hotspot analysis,and other methods were used to analyze the winter drought evolution characteristics of the entire Inner Mongolia region and the five main vegetation types.Results show that in the past 40 years,the overall SPEI in Inner Mongolia has shown an increasing trend in winter,and aridification varies among different vegetation and months,with a few vegetation and months tending toward hu-midification.The change patterns in Inner Mongolia mainly include three types:oscillating hot spots,oscillating cold spots,and undetected patterns.From a seasonal perspective,hotspots are primarily distributed in most areas of western Inner Mongolia,as well as in Xing'an League and Tongliao City in the east.On a monthly scale,hot-spots often appear in the central and western regions of Inner Mongolia.With regard to drought frequency and fre-quency statistics,mild drought events have the highest frequency,whereas winter drought events occur more fre-quently and seriously in desert grasslands and neighboring desert areas.