Study on the evolution of extreme precipitation in southern cities under the background of climate change

Based on the 61 years (1960 to 2020) measured rainfall of Dongguan meteorological station, the evolution characteristics of extreme precipitation in Dongguan City were analyzed by using M-K catastrophe test, wavelet analysis and R/S analysis. The results show that: ①The extreme precipitation in Dongguan City has obvious annual and generational changes. The annual extreme precipitation series shows an increasing trend. In the 1970s, 1980s and 2000s, the average and maximum daily maximum rainfall were relatively large, while the average of the maximum daily rainfall in the 1960s was the smallest, and the maximum daily rainfall in the 1990s was the smallest. ②Extreme precipitation in Dongguan City showed a downward trend from 1960 to 1974 and an upward trend from 1975 to 2020, but the upward or downward trend was not significant and there was no obvious abrupt point. Before and after 1975, the annual maximum daily rainfall at Dongguan station changed obviously, and the average annual maximum daily rainfall from 1975 to 2020 increased by 19.63% compared with the average from 1960 to 1974. ③Extreme precipitation in Dongguan City has a main cycle of 4 years and sub-cycle of 21 years. ④In the future, the extreme value of precipitation in Dongguan City will still have a weak increasing trend, and the continuous intensity will weaken year by year.