南澳县降水特征分析

Characteristics of precipitation in Nanao

利用统计、Matlab小波分析法,对南澳县1957—2009年的年、月降水量进行分析和计算,结果表明:南澳县年降水主要集中在4—9月份,占全年降水量的80.5%呈现双峰型,6月份是最高峰,8月份为次高峰,分别分布于前、后汛期;多雨期与少雨期交替变化,在少雨年份的转折期都有一年对应的多雨年份;53a来南澳的年降水量、后汛期降水量均有一个28a的准周期变化,前汛期降水量在1959—1994年存在准12a的周期。

According to methods of statistics and Matlab wavelet, this paper analyses annual and monthly precipitation in the years from 1957 to 2009 in Nanao. The results show that： annual precipitation is mainly concentrated in the months from April to September, which accounts for 80.5% precipitation and presents double peak; the highest peak of precipitation is in June and the secondary peak is in August, which is distributed before and after the flood season; the rain period and less rain period are alternated; during less rain period, there is always corresponding rain period; for over 53 years, the average annual precipitation and precipitation after the flood season have the same quasi-28-year-periodic cycle, meanwhile the precipitation before the flood season has the quasi-12-year cycle in the years from 1959 to 1994.