Spatiotemporal Change Characteristics of Extreme Precipitation in Southwestern China and its Relationship with Intense ENSO Events

Under the background of global warming， it is of great application value to study extreme precipitation events in four southwestern provinces and cities in China， which are vulnerable to the ecological environment and sensitive to climate change.Based on the daily temperature and precipitation data of 93 weather stations from 1969 to 2020， by selecting 11 extreme precipitation indices， using linear regression analysis， M-K mutation test， EOF analysis， and other methods， this paper not only analyzed the spatiotemporal variation characteristics of extreme precipitation events in Southwestern China in 52 years， but discussed the relationship between extreme precipitation indices and intense ENSO events by calculating the composite ratio.The results showed that： （1） The overall frequency and intensity of precipitation in Southwestern China increased from 1969 to 2020， and extreme precipitation trend increased.The four regions divided by topography also showed precipitation characteristics of different degrees； （2