Classification of Persistent Heavy Rainfall Events over Southern China during Recent 30 Years

The persistent heavy rainfall events (PHREs) over southern China during 1981-2011 are classified by utilizing the daily precipitation data at 752 stations in China. PHREs in the Yangtze and Huaihe River Valley (YHRV) and PHREs in South China (SC) during 1981-2011 are selected on the basis of the following criteria: More than 10 grids 0.25°(latitude)×0.25°(longitude) in the area with daily precipitation of more than 50 mm lasting more than five days and rainband coincidence degree greater than 20%. The statistics reveal that 31 PHREs in the YHRV were concentrated between mid-June to mid-July with an average duration of 8.29 days, whereas 34 non-typhoon PHREs in SC were concentrated in June and July with an average duration of 6.24 days. Moreover, the frequency and intensity of these two types changed in decadal growth. PHREs affected by the typhoon systems in the YHRV were concentrated between mid-July and early August. Those occurring in SC were concentrated from July to September, and their frequency and intensity have increased since 2000. Objective pattern correlation statistics are used to classify and discuss the non-typhoon PHREs in detail. PHREs in the YHRV are divided into three types: (A) main rainbelt to the south of the Yangtze River (YR), (B) main rainbelt to the north of the YR, (C) main rainbelt along the YR, and PHREs in SC are classified into two types: (E) main rain belt to the east of the Yunnan-Guizhou Plateau and (F) main rainbelt located over the Yunnan-Guizhou Plateau and Guangxi Province. On the basis of such classification, the mechanisms of PHREs will be discussed in future studies.