四川盆地降水量变化特征分析

Analysis of Variation Characteristics of Precipitation in Sichuan Basin

基于四川盆地内8个雨量站1954—2010年的月降水资料,运用降水集度、线性回归分析、滑动平均法、距平百分率、Kendall秩次相关法、小波分析、Mann-Kendall检验法以及滑动t检验法,对四川盆地降水量年内分配情况、年和四季降水量变化趋势、周期及突变性进行了分析。结果表明,四川盆地降水量年内分配呈季节性变化;年及四季降水量均呈减少趋势,其中,年和秋季降水量减少趋势在95%置信区间内显著;年、秋季和冬季降水量变化周期较短,均小于10 a;春季和冬季降水量不存在明显的突变点,年和秋季降水量突变开始的时间分别为1985年和1997年,夏季存在2次突变,突变点分别为1979年和1997年。

Based on the data of monthly mean precipitation recorded at 8 weather stations in Sichuan basin from 1954 to 2010, the characteristics of the change in precipitation were analyzed by precipitation concentration index, linear regressive method, moving average curve, anomaly precent, Kendall rank test method, Morlet wavelet analysis, Mann-Kendall rank statistic method and moving t statistic method. The results indicated that the annual distribution of precipitation was regular in a certain degree with the seasonal changes. The fluctuation of annual and the four seasons precipitation exhibited a tendency of decreasing, precipitation in annual and autumn decreased significantly at 0.05 significant level. The major period was less than 10 years in annual, autumn and winter rainfall. 1958 and 1997 were the abrupt precipitation in annual and autumn. The two abrupt of summer precipitation were 1979 and 1997.