水库对区域经济发展和人民生活都具有重要作用，近年来新疆极端降水频发，对水库安全影响较大，目前针对新疆水库降水的研究较少，不能有效为水资源利用和水库调度等提供科学参考。本文利用伊吾国家气象站1961—2022年逐日降水资料和2009—2022年逐小时降水资料，分析新疆哈密市伊吾县峡沟水库集水区不同时间尺度和不同等级降水的长期变化特征，结果表明：（1） 1961—2022年汛期，峡沟水库集水区平均降水量呈弱增加趋势，最大连续无降水日数呈显著增加趋势；总降水日数和最大连续降水日数均呈显著减少趋势，降水量增加，降水日数显著减少，可能导致该区域的降水强度进一步增强。（2） 汛期降水以小雨为主，过去62 a，该区域小雨和中雨的日数呈减少趋势，大雨和暴雨的日数呈增加趋势；暴雨雨量占汛期总降水量的比例最高接近50.0%，暴雨雨量增加是峡沟水库集水区汛期降水量增加的主要原因。（3） 降水量日变化呈现随降水等级加强，大值时段逐渐前移的特征，即小雨的大值时段出现在下午，中雨在中午，大雨在上午，暴雨在早晨。除暴雨外，其他等级降水频次的高值时段均在白天。各等级降水平均降水强度的日变化曲线均呈多峰型，且差异较大；小雨和中雨的累计降水频次与累计降水量的关系比降水强度更密切，大雨和暴雨的平均降水强度与累计降水量的关系则比累计降水频次更密切。

Reservoirs play a pivotal role in regional economic development and societal well-being. In recent years, Xinjiang has experienced frequent extreme precipitation events, which pose significant challenges to reservoir safety. However, research on precipitation characteristics specific to Xinjiang’s reservoirs remains limited, preventing scientific guidance for water resource utilization and reservoir management. Using daily precipitation data from 1961 to 2022 and hourly precipitation data from 2009 to 2022 in the Xiagou reservoir watershed of Yiwu County, Hami City, this study analyzes long-term variations at different time scales and precipitation levels. The findings indicate following points: (1) During the rainy season from 1961 to 2022, the average precipitation in the Xiagou reservoir catchment area showed a weak increase, and the number of days with discontinuous precipitation enhanced significantly. The total number of precipitation days and the maximum number of continuous precipitation days reduced evidently. Together, these trends may lead to further enhancement of the precipitation intensity in the region. (2) The rainy season is mainly characterized by light rainfall; however, over the past 62 years, the number of light and moderate rain days has declined, unlike heavy and torrential rain days. The highest proportion of rainstorms to total rainfall during the rainy season was approximately 50.0%, which was the main reason for the increase in precipitation during the rainy season in the Xiagou reservoir catchment area. (3) Daily precipitation values displayed a rising pattern as the precipitation intensity strengthened. For instance, high values for light, moderate, heavy, and torrential rain occurred in the afternoon, midday, morning, and early morning, respectively. Except for torrential rain, high values for other precipitation levels were predominantly observed during the daytime. The daily variation curves for the average precipitation intensity exhibit multiple peaks with remarkable variations. The relationship between cumulative precipitation frequency and amount was more closely associated with light and moderate rain than with precipitation intensity. Conversely, the relationship between average precipitation intensity and cumulative precipitation amount was more closely related to heavy and torrential rain than to cumulative precipitation frequency.