黄河上游天然径流变化特性分析

The characteristics of natural streamflow in the upstream of the Yellow River

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。

Runoff time series contains wealthy information, which can reveal the intrinsic characteristics and evolution regular of runoff. The information can be used to predict the feature development of runoff. Based on the annual streamflow time series from Tangnaihai station from 1956 to 2012 in the upstream of Yellow River, using statistic analysis, trend analysis, Mann -Kendall non -parameters test and wavelet analysis method, the characteristics of natural streamflow in the upstream of Yellow River were analyzed. The results showed that the annual average streamflow was 627.9m3/s and expressed a downtrend with a scale of decrease 2.65m3/s annual ; a comparatively greater difference existed among the annual streamflow and the extreme ratio （K） reached 3.1. Asymmetrical distribution feature of runoff during the year displayed as a situation that the runoff from July to September accounted for 46.75% of total runoff; the mutation occurred in 1992, before and after which the average runoff were 666.05m3/s and 545.75m3/s respectively; the multi - level time - scale structure characteristics of runoff tima, e series were revealed with the method of Morlet wavelet transform, and the first and second primary periods were 12 and 22 years which expressed as dominant role for runoff evolution.