Spatiotemporal variations of precipitation extremes of China during the past 50 years (1960–2009)

Abstract

Extreme weather events have become more frequent and intense under global warming in recent years, which has attracted much attention of scholars at home and abroad. In this paper, we used data sets of daily precipitation recorded at 499 meteorological stations to analyze the temporal and spatial variations of precipitation extremes in China over the past 50 years (1960–2009). Through the comparison of detrended fluctuation analysis (DFA) and the percentile method, DFA was selected to define the thresholds of precipitation extremes in China. Temporal variations of extreme precipitation amount, frequency, and intensity were analyzed in four major regions: Northwest China, the Qinghai-Tibet region, North China, and South China. Spatial distributions were obtained by the Kriging interpolation method, and then, we examined the varying tendencies of extreme precipitation amount, frequency, and intensity by the Mann-Kendall test. The results show that increasing trends are dominant for all indices over China; extreme precipitation amount and frequency appear to have risen since 1970–1979, but there are some regional differences. The Qinghai-Tibet region and South China have an ascending trend, and Northwest China maintains balance while North China has a descending trend. The amount and intensity of precipitation extremes are decreasing from southeastern coastal areas to northwestern inlands, and the frequency of precipitation extremes is randomly distributed. However, they are all high in the Sichuan Basin, the middle and lower Yangtze River, and the southern part of South China. Trends of most stations are statistically insignificant, but the percentage of stations with a significant increased trend in the Qinghai-Tibet region is larger than that of other regions.