Temporal and Spatial Variations of Extreme Precipitation in the Main River Basins of China in the Past 60 Years

As a consequence of global warming, China has experienced increasing extreme precipitation events and secondary disasters such as floods and droughts, which have had significant effects on the ecosystem, production, life, and society. This study uses daily station precipitation records to systematically analyze the long-term trends in precipitation over China and nine river basins from 1961 to 2017. It uses ten precipitation indices specified by the Expert Team on Climate Change Detection and Indices (ETCCDI). In addition, the detectability of the trends in several precipitation characteristics is also examined based on the field significance test. The findings indicate that the extreme precipitation over China shows obvious regional features. The number of stations showing increasing trends in mean precipitation, precipitation intensity, extreme heavy precipitation, and continuous heavy precipitation exceeds the decreasing trends. However, the observed percentage of stations with significant increasing trends differs statistically from the internal climate variability but is influenced by the external forcings. Furthermore, for the majority of the station, the consecutive dry days (CDD) decreases, and the observed percentage of stations with significant decreasing trends is also related to the external forcing. Across the continental river basins, strengthened mean precipitation, precipitation intensity, extreme heavy precipitation, continuous heavy precipitation, and reduced CDD can be observed, which can be attributed to the influence of external forcings. Flood are becoming frequent in the continental. Strengthened mean precipitation and external force-related increase in heavy precipitation can be found across the Yangtze River, Pearl River, and southeastern river basin. The southwestern river basin has experienced an increase of extremely heavy precipitation, but there is a risk of increasing drought as the CDD lengthens for the majority of stations. Several precipitation indices and the area-averaged mean for the Yellow River, Haihe River, Huaihe River, and Songliao River basin. The various responses of precipitation characteristics to global warming suggest that the different river basins will experience a variety of climate disasters.