南水北调中线水源地堵河流域降水变化分析

利用线性回归法、Man-Kendall检验法、R/S分析法结合Hurst系数等方法,分析了1964-2014年堵河流域降水量的变化情况。结果表明,堵河流域年降水量有明显的年际变化,季节降水量以夏季最多,春、秋两季次之,冬季最少。除夏季降水量表现为增加趋势外,年降水量与其他3个季节的降水量均表现为减少趋势,秋季降水量变化率达到-14.8 mm/10年。堵河流域除秋季降水量外,年及其他季降水量UF曲线均没有超过显著性水平线,认为没有明显的突变点;1985年为秋季降水量的突变年份。堵河流域除秋季降水量序列具有一定的相关性,其变异程度为中变异,降水减少趋势变化的持续性比较明显外,年降水量及其他季节降水量序列变异程度均不显著。

Variation of Precipitation in the Duhe River Basin of the Water Source in Central Line Project of South-to-North Water Diversion

The variation of precipitation in the Duhe River Basin during 1964~2014 were analyzed by using the linear regression method, Mann-Kendall trend test, the R∕S analysis and Hurst coefficient. Results indicated that the variation of annual precipitation was significant in the Duhe River Basin. Meanwhile, the precipitation amount in summer had the greatest proportion of the annual total precipitation. Additionally, the precipitation amount in spring takes the second place, which followed by the precipitation amount in autumn and winter. The total precipitation in summer increase faintly, while the annual total precipitation, the precipitation amount in autumn and spring showed a stable decreasing trend. Besides, the precipitation amount in winter did not indicate a significant changing tendency. There were not abrupt changes and periods on annual and seasonal precipitation, except autumn precipitation (1985). The results indicated that the seasonal and annual precipitation alteration in Duhe River Basin was not remarkable, except that the alteration degree of autumn precipitation was moderate alteration.