长江上游小江流域降水趋势与泥石流侵蚀输沙量分析

Analysis of Rainfall Trends in Xiaojiang River Basin in Upper Reach of Yangtze River and Eroded Sediment of Debris Flow

运用Mann-Kendall(M-K)非参数检验法分析降水趋势,研究了1950 s^1990 s长江上游小江流域降水变化特征。结果表明:1990 s长江上游小江流域年降水变化以显著增加为主要特点,M-K检验表现为显著增加趋势(95%的置信度)。该特点与小江流域蒋家沟泥石流在90年代出现的侵蚀输沙量的大量增加有相当紧密的关系。1990 s比1965~1989年期间平均每年泥石流要多侵蚀输沙91万m3。

The Mann-Kendall （M-K） statistical test method was used to analyze the rainfall data of Xiaojiang River basin in the upper reach of Yangtze River from 1950 s to 1990s in this article. The result of M-K test with 95% confidence interval shows that the annual rainfall amount has a notably increasing trend in 1990 s in the Xiaojiang River basin. The tendency of the increase sediment delivered by debris flows at Jiangjia ravine located in Xiaojiang River basin has close relation with the increase of the annual rainfall in 1990 s. The average annual sediment yield by debris flows in 1990 s is about 0. 91 million more than that between 1965 and 1989.