摘要:
汉江流域20世纪90年代连续枯水年引起了社会各界关于南水北调中线工程调水安全的担忧，因此对汉江上游流域的降水和径流变化趋势和周期特性进行统计分析十分必要。利用Mann-Kendall检验、Spearman检验、线性回归分析等方法分析了汉江上游流域降水、径流变化趋势，结果表明在显著性水平α = 0.05上，汉江上游径流和降水量变化趋势均不显著。利用小波分析研究得到汉江上游径流量系列存在7~10年和20~25年两种时间尺度的周期性变化规律。研究表明20世纪90年代连续枯水年主要是由于降水减少所致，是处于径流丰枯周期性变化过程中的枯水期。
Abstract:
Continuous dry of the Hanjiang basin during 1990s has aroused concerns about security of the middle route project of south to north water diversion project. As a result, it is very important to analyze the change trend and cycle statistics of runoff series in the upstream of Hanjiang. Mann- Kendall, Spearman and Linear regression analyses were used to analyze the change trend of runoff series. It is shown that on the level of significance of 0.05, the runoff and precipitation trends were not significant. Wavelet analysis was used to analyze the cycle statistics. The result shows that runoff series has 7 to 10, and 20 to 25 years of the time scale of the cyclical change rule. Research shows that the generation of continuous dry years in the Hanjiang basin is mainly due to a decrease of precipitation, and that runoff is in periodic variation during low water period.