哈密市伊吾县峡沟水库集水区汛期降水特征

Reservoirs play a pivotal role in regional economic development and societal well-being. In recent years, Xinjiang has experienced frequent extreme precipitation events, posing significant challenges to reservoir safety. However, research on precipitation characteristics specific to Xinjiang's reservoirs remains limited, impeding scientific guidance for water resource utilization and reservoir management. Utilizing 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 analyzed long-term variations in different time scales and precipitation levels. The findings indicate: (1) During the rainy season from 1961 to 2022, the average precipitation in the Xiagou Reservoir catchment area showed a weak increasing trend, and the number of days with no continuous precipitation showed a significant increasing trend. The total number of precipitation days and the maximum continuous precipitation days both show a significant decreasing trend. The increase in precipitation and the significant decrease in precipitation days may lead to further enhancement of precipitation intensity in the region. (2) The rainy season is mainly characterized by light rain, yet over the past 62 years, the number of light rain and moderate rain days has decreased while heavy rain and torrential rain days have increased. The highest proportion of rainstorm rainfall to the total rainfall in rainy season is close to 50.0%, and the increase of rainstorm rainfall is the main reason for the increase of rainfall in rainy season in Xiagou reservoir catchment area. (3) Daily precipitation displays a pattern of advancing high values as precipitation intensity strengthens. For instance, high values for light rain occur in the afternoon, moderate rain at midday, heavy rain in the morning, and torrential rain in the early morning. Except for torrential rain, high values for other precipitation levels are predominantly during the daytime. The daily variation curves for average precipitation intensity exhibit multiple peaks with significant differences. The relationship between cumulative precipitation frequency and cumulative precipitation amount is more closely associated with light and moderate rain than with precipitation intensity. Conversely, the relationship between average precipitation intensity and cumulative precipitation amount is more closely related to heavy and torrential rain than to cumulative precipitation frequency.