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利用黄河上游唐乃亥水文站1956~2012年57年的径流时间序列资料,采用统计分析法、趋势分析法、Mann-Kendall非参数检验法和小波分析法分析了黄河上游径流年内分布特征、径流年际变化趋势、突变特征及其周期性。结果表明:黄河上游多年平均径流量为627.9m~3/s,径流在年际间表现出较大的差异性,极值比K达到3.1;径流在年内分布不均匀,其中7~9月三个月的径流占全年径流量的46.75%;年径流量总体呈下降趋势,下降率为2.65m~3/s/年;黄河上游年径流量在1992年发生突变,突变前后年平均径流量分别为666.05m~3/s和545.75m~3/s,相差120.3m~3/s;黄河上游径流变化存在着多层次的时间尺度结构,径流演变的第一和第二主周期分别为12年和22年,它们控制了流域径流的演变过程。
Based on the runoff time series data of Tangnaizi Hydrological Station from 1956 to 2012 in the upper Yellow River, statistical analysis, trend analysis, Mann-Kendall nonparametric test and wavelet analysis were used to analyze the annual distribution characteristics of runoff in the upper Yellow River, runoff interannual Change trends, mutation characteristics and their periodicity. The results showed that the mean annual runoff of the upper reaches of the Yellow River was 627.9m ~ 3 / s, and the runoff showed a great difference in the interannual period with the extreme value ratio K up to 3.1. The runoff was unevenly distributed during the year, of which, from July to September The monthly runoff accounted for 46.75% of the annual runoff; annual runoff decreased overall, with a decrease rate of 2.65m ~ 3 / s / year; annual runoff in the upper reaches of the Yellow River had a mutation in 1992, and annual average runoff before and after the mutation Which are 666.05m ~ 3 / s and 545.75m ~ 3 / s respectively, with a difference of 120.3m ~ 3 / s. There are multi-level time-scale structures of runoff in the upper reaches of the Yellow River, and the first and second main cycles of runoff are 12 Years and 22 years, they control the evolution of watershed runoff.