Analysis on the evolution of precipitation in the Southern Region of Dalian City under the background of global climate warming

To study the impact of climate change on precipitation, 66 years of precipitation data from Dalian Meteorological Station from 1951 to 2016 were selected. The moving average method, Mann-Kendall test, rescaled range (R/S) analysis, Pettitt mutation test, sliding T test, and Morlet wavelet analysis were used to analyze the trend, mutation,period of annual precipitation series,and precipitation structure evolution trend. The results showed that the annual precipitation series in the southern region of Dalian from 1951 to 2016 showed an insignificant downward trend, and it is predicted that the precipitation will continue to decrease in the next 10 years; The mutation year of the annual precipitation series is 1979; There are four types of periodic changes in the annual precipitation series, with four distinct main periods of 58, 19, 25, and 5 years, respectively. The precipitation event is dominated by rainstorm, and the duration is mainly 2 d. The occurrence rate and contribution rate of precipitation events of 5 d and above show a significant downward trend, while the occurrence rate and contribution rate of moderate precipitation and 1-2 d precipitation show an upward trend. By studying the evolution of precipitation, some reference is provided for water resource planning and utilization, as well as for preventing drought and flood disasters.