Analyses of Seasonal Variation Characteristics of the Rainfall Duration over China
Using 12-hourly station rain-gauge data at 588 stations during 1969-2008, this paper analyzes the spatial characteristics and seasonal variation of rainfall durations over China. The result shows that in south of 35°N, the annual mean averaged rainfall duration over eastern and western regions is longer than that over the middle region, while over north of 35°N, northwestern China and the west of Inner Mongol,the averaged rainfall duration is the shortest all over China, and the rainfall duration over the north of northeastern China is longer. According to the duration time, precipitation events are classified. Over the three regions of eastern China （southeastern China, the region of Jianghuai and Huanghuai, and the regionof northeastern China and the north of North China）, the percentages of the short-duration rainfall （1 time duration for 12 h） to the total rainfall gradually increase during the whole year for both amount and fre- quency, while those of long-duration rainfall （no less than 3 times duration） decrease. The seasonal varia- tion of averaged rainfall duration in China reasonably reflects the spring persistent rain over southeasternChina, the Meiyu, the summer rainy season over northeastern China and the north of North China, the autumn rain over Guanzhong Basin and Hanshui River Valley and the summer rain over the Tibetan Plat- eau and southwestern China. The averaged rainfall duration is long in autumn and winter over southeastern China, in the first dekad of October over Jianghuai and Huanghuai region and in the last dekad of Octoberover southwestern China, which is not in accordance with attributed to the increasing frequency of the long-duration duration rainfall. Subseasonal variation of averaged rainfall corresponds to the ＇northward advance and the southward the variation of rainfall. These features can be rainfall and decreasing frequency of the short- duration over the three regions of eastern China retreat＇ of the monsoon rain belt.
averaged rainfall durationseasonal variation of rainfallshort-duration rainfalllong-durationrainfall
国家科技期刊平台
NSTL
万方数据
维普
