基于时间序列的滇池流域降雨变化特征分析

针对云南省连续4年大旱、降雨偏少的问题,基于滇池流域内18个雨量站1965~2011年降雨资料,分析了降雨年际年代变化特征,采用线性回归法和Mann-Kendall非参数检验方法对年降雨序列进行趋势预测,利用Morlet小波进行周期分析,并通过小波系数方差检验年降雨序列主周期。结果表明,滇池流域降雨年际变化大,变差系数在0.17~0.24之间;年内分配不均,雨季占全年降雨量的87%左右;年降雨序列呈减少趋势,但减少趋势不明显;降雨序列主周期为23年,次周期分别为4、15年。

Analysis of Rainfall Variation in Dianchi Basin Based on Time Series

For four consecutive years of drought in Yunnan Province, and less than normal rainfall, data series of 18 precipitation stations in Dianchi Basin from 1965 to 2011 are used to analyze the inter-annual variation of rainfall. The linear regression method and Mann-Kendall non-parameter test method are used to predict the trend of rainfall. And then Morlet wavelet is applied to analyze the cycle of rainfall series. Finally, the variance of wavelet coefficients is used to test the main cycle of the annual rainfall series. The results show that the variability of rainfall are relatively large in Dianchi Basin in different years; the variation coefficient is in the range of 0.17-0.24; the rainfall is extremely uneven during the year; the precipitation in rainy season is about 87% in the annual rainfall; rainfall series appears downward trend, but the trend is not obvious; the primary period of rainfall series is 23 years, and two secondary periods are 4 years and 15 years, respectively.