伊犁河流域是天山降水量最大的区域，也是强降水频发区域，研究不同时间尺度极端降水精细化特征对气象预报、防洪减灾有科学意义。利用伊犁河流域地区2010—2021年暖季（5—8月）近300个区域自动站小时降水数据，以最新一代全球降水测量计划（GPM IMERG）卫星降水产品为初始场，实况降水为观测场，通过最优插值（OI）将偏差订正后的IMERG降水量估计值与雨量计实况相结合，运用概率密度匹配与最优插值两步融合校正方法（PDF-OI），获得高分辨率（0.1°×0.1°）逐小时多源降水融合资料，分析伊犁河流域极端降水特征。结果表明：（1） 小时降水量极端值（22.5~38.9 mm）出现在流域北部及东段海拔较高的山区；极端降水强度在2000 m的中海拔平山区较强，强度与极端降水阈值空间分布相似，而频次分布则不同，频次随海拔升高逐渐增多。（2） 小时极端降水日变化在流域北部最大，河谷山区次之，东段居第三位，而流域南部最小；极端降水频次日变化流域南部最大，河谷山区次之、东段居第三位、北部最小。（3） EP_{1 h}（小时极端降水）阈值最大值8.5 mm、最小值1.2 mm，EP_{3 h}（3 h极端降水）阈值空间分布与EP_{1 h}相似，即降水阈值由流域中海拔区域向高海拔山区逐渐减小，EP_{6 h} （6 h极端降水）与EP_{12 h} （12 h极端降水）阈值分布从2000 m和3000 m开始向高海拔区域逐渐减小。

The Ili River Basin is the area with the highest precipitation in the Tianshan Mountains and frequently experiences heavy precipitation. Studying the fine characteristics of the precipitation at different time scales can advance meteorological forecasting and flood control. Using the hourly precipitation data from nearly 300 regional automatic stations in the Ili River Basin during the warm season (May-August) from 2010 to 2021, taking the latest generation of the Global Precipitation Measurement Mission satellite precipitation product as the initial field, and taking the actual precipitation as the observation field, this study combines the bias-corrected IMERG precipitation estimates with the rain gauge observations through optimal interpolation (OI). The probability density function-OI two-step fusion correction method yielded high-resolution (0.1°×0.1°) hourly multi-source precipitation fusion data, from which the extreme precipitation characteristics in the Ili River Basin were analyzed. The results show that: (1) extreme hourly precipitation events (22.5-38.9 mm) occur in the northern and eastern high-altitude mountainous areas of the basin, whereas the extreme precipitation intensity is stronger in the mid-altitude plain areas at 2000 m. The spatial distribution of the extreme intensity is similar to that of the extreme precipitation thresholds but exhibits a different frequency distribution; specifically, a gradual increase of frequency with altitude. (2) The diurnal variation of hourly extreme precipitation is largest in the northern part of the basin, second-largest in the Wusun Mountain area, third-largest in the eastern section, and smallest in the southern part of the basin. In contrast, the diurnal variation of extreme precipitation frequency is largest in the southern part of the basin, followed by the Wusun Mountain area, the eastern section, and the northern part. (3) The hourly extreme precipitation (EP_{1 h}) threshold ranges from 1.2 to 8.5 mm. The three-hourly extreme precipitation (EP_{3 h}) threshold is distributed similarly to that of EP1h, showing a gradual decrease from the mid-altitude area to the high-altitude mountainous area of the basin. The thresholds of the EP_{6 h} and EP_{12 h} gradually decrease from 2000 m and 3000 m to the high-altitude areas.