Analysis of extreme rainfall characteristics in the Huanren Basin of the Hunjiang River

Studying the characteristics of extreme rainfall changes in the Huanren Basin is of great significance for water resource management and flood control safety in the basin. Based on daily rainfall data from 19 rainfall stations in the Huanren Basin from 1980 to 2023, extreme rainfall changes were analyzed using methods such as trend analysis, moving average, and wavelet transform. Research has shown that extreme rainfall events throughout the year have significantly increased in frequency and intensity, with a significant upward trend in summer frequency and intensity, a significant increase in autumn frequency, and a more prominent increase after 2010. Each extreme rainfall index shows a significant upward trend, especially the extreme rainfall value is significantly higher than before 2000, and the ordinary daily rainfall intensity, the number of heavy rain days and the number of rainstorm days show a slow upward trend. From the change trend and periodicity of each index, there is a certain periodicity in the change of each extreme rainfall index. The first main periods of extreme rainfall values and rainstorm days are 5 years and 14 years respectively, and the first main periods of other indexes are generally 20～22 years. The research results can provide support for extreme event response and flood disaster prevention in Huanren Basin.