Analysis of climate change characteristic of rainstorm in Chongqing in recent 45 years

Based on the daily rainfall data of 34 observational stations in Chongqing from 1971 to 2015, the climatological characteristics and changes of rainstorm days, intensity and contribution rate in Chongqing in recent 45 years are analyzed by using statistical diagnosis methods such as linear trend analysis, Mann-Kendall test and wavelet analysis. The results show that in the past 45 years, the geographical distribution of annual average rainstorm days in Chongqing shows a decreasing trend from mountain to plain. The maximum appears in the eastern part of Chongqing, and the two centers are located in Kaizhou (5.0 d) and Youyang (3.9 d), respectively. The minimum values appeared in Shizhu, Jiangjin and Qijiang (2.2 d). The variational trend of rainstorm days in Chongqing is not obvious, but it has obvious interannual and interdecadal variation. The annual average and summer rainstorm intensity are increasing in Chongqing. The contribution rate of annual and summer rainstorm in Chongqing increased significantly.