华南前汛期降水变率的分析

ANALYSIS OF RAINFALL VARIABILITY DURING THE FIRST RAINY SEASON IN SOUTH CHINA

利用华南１６个站１９５１～１９９６年逐年、月和候降水量资料，分析了前汛期（４～６月）总降水量及前汛期开始期的变化特征．结果表明，全区前汛期总降水量变化有相当好的一致性．以降水异常的空间分布基本可划分成６种类型．根据候降水量变化，逐年前汛期开始期大体可分成４类，即：全区偏早（１４年）；全区偏晚（１６年）；东部早西部晚（７年）和东部晚西部早（９年）．总之。

he variability of total rainfall for the period of April to June and variation of the beginning date of the first rainy season were studied by using annual, monthly and pentad rainfall data of 16 stations from 1951 to 1996 over South China. The results indicate that there is a good consistency for the variations of total precipitation during the first rainy season over South China. The spatial distribution of rainfall anomaly could be divided into 6 types. Based on the variation of pentad rainfall, the beginning date of annual first rainy season could be divided into 4 types, i. e. early in the most of the region (14a), later in the most of the region (16 a), early in the east and later in the west (7a), and later in the east and early in the west (9 a). Generally speaking, both the precipitation and the beginning date during the first rainy season have obvious interannual and interdecadal changes.