基于Mann-Kendall法的径流丰枯变化过程划分

提出利用Mann-Kendall法,将已有径流时间序列划分为若干个时间序列,计算出每一个时间序列的U值,以U-t曲线的变化趋势来划分径流序列的丰枯变化过程;以闽江流域竹岐站和白山水库的径流序列为例进行分析。结果表明:闽江流域径流丰枯变化过程为1946-1996年,白山水库丰枯变化较闽江流域频繁,分别为1946-1966年和1967-1975年,且第三个丰枯变化过程还没有完成。由于Mann-Kendall法属于非参数检验,受样本的分布类型限制比较少、样本中可允许少量漏测值以及方法比较简单适用等特点,因此,Mann-Kendall法可以和应用差积曲线法划分丰枯变化过程的方法互为补充。

Division of variation process of high and low runoff based on Mann-Kendall method

The paper presented a method to divide the variation of high and low flow by using the Mann-Kendall method. Firstly, a runoff time series were divided into several time series, and then, the U values of the series were calculated to obtain. Finally, the variation process of high and low runoff was determined according to the U-t curve. The runoff series of Zhuqi gauge station in the Minjiang River watershed and Baishan reservoir were analyzed as example. The results showed that the annual stream flow sequence with variation process of high and low runoff was 1946to 1996in the Mingjiang River.The variation of high and low runoff in the Baishan reservoir was 1946to 1966and 1967to 1975respectively, and the third variation one wasn't completed up to now. The result also showed that the Mann-Kendall method was applicable in dividing the variation of high and low runoff.