长江大通站径流量变化特征分析

Analysis of Runoff Change Characteristics at Datong Station of Yangtze River

综合采用Mann-Kendall趋势检验、Pettitt突变点检验、Morlet小波分析及径流年内分配量化研究方法分析了长江大通站1946～2009年径流的变化趋势、突变、周期和年内分配特征。结果发现大通站年均、洪、枯季流量无明显变化趋势，但月均流量有明显变化趋势；年均流量无显著突变，但洪、枯季、月均流量均存在显著突变；流量序列存在10年以上的年代周期与10年以内的年际周期；径流年内分配在20世纪60、70、90年代相对集中，在21世纪初则相对均匀，年内径流主要集中于7、8月，年内变幅在20世纪60年代较大．在21世纪初较小。分析了大通站径流变化原因，以期为流域水资源的合理开发利用提供科学依据。

Trend, change point, period and annual distribution of runoff at Datong Station in Yangtze River from 1946 to 2009 are investigated by using the nonparametric Mann-Kendall test, Pettitt Mann Whitney change point statistics, Morlet wavelet transform and annual distribution quantitative methods. It is found that the annual and seasonal run- off series at Datong Station have little trends but the monthly runoff series have obvious variation trends; the annual series has no change point while the seasonal and monthly runoff series have significant change points, the runoff series also have periods of over and within 10 years; furthermore, annual distribution of runoff series is more concentrated in 1960s, 1970s and 1990s while evener in 2000s; the annual runoff mainly concentrates in July and August; the annual variation range of runoff is larger in 1960s but smaller in 2000s. Besides, the reasons of runoff change are also analyzed, which provides scientific basis for water resources development and utilization in basin.