Analysis on the Characteristics of Extreme Precipitation in Southwestern China

In this paper, the daily precipitation and temperature data from 1971 to 2017 in Southwestern China were used to study the changes in extreme precipitation. The percentile threshold method was used to define extreme precipitation, and six extreme precipitation indexes were obtained through the calculation and statistics of daily precipitation. After research and analysis, the following conclusions were obtained: from the time point of view, the total precipitation in Southwestern China decreased in the past 47 years, but the frequency and intensity of extreme precipitation have increased. From the spatial point of view, the ratio and intensity of extreme precipitation in the east part of Southwestern China were higher than those in the west part of Southwestern China. The increase in summer averaged temperature will lead to a steady increase in extreme precipitation. Still, the increase of daily average temperature will cause the extreme precipitation to increase slowly and then suddenly decrease, it shows that extreme precipitation in Southwestern China has more uncertainty with the increase of temperature, and extreme precipitation tends to develop in a trend of higher frequency, shorter time, and more vigorous intensity. The change rate of extreme precipitation with summer averaged temperature was 8.52%/℃, which was higher than that of the C-C equation.