1961-2022年新疆南部降雨和极端降雨特征OA

Using daily rainfall data from 45 national meteorological observation stations in southern Xinjiang of China from 1961 to 2022,we analyzed the spatiotemporal distribution and variability of rainfall,identified ex-treme rainfall thresholds,and examined extreme rainfall characteristics.The results show that(1)Over the past 62 years,the region with the highest and most rapidly increasing annual average rainfall in southern Xinjiang has been located in the middle mountain belt at an altitude of 1500-2500 m,with a growth rate of 5.4 mm·(10a)-1.This increase is mainly reflected in the greater number of rainfall days,particularly large-scale rainfall days,while the increase in heavy-rainstorm-level rainfall and above is especially pronounced.(2)Based on a comparative analysis using the percentile method,the 99th percentile was identified as the threshold for extreme rainfall in southern Xinjiang,corresponding to 14.1-35.4 mm.Thresholds in the western and mountain-adjacent re-gions are higher than those in the eastern basin-desert areas,and the extreme rainfall threshold has increased at a rate of 0.7 mm·(10a)-1.Stations with the most rapid increases are primarily located in the mountainous areas of Kashgar,western Hotan,and northern Bayingol Mongolian Autonomous Prefecture.(3)Over the past 62 years,the number of extreme rainfall events in southern Xinjiang has generally ranged from 10-20 times,while in the Tianshan Mountains,events can persist for more than 20 times.Extreme rainfall events have increased in frequen-cy at a rate of 0.9 events per decade.