沁河流域汛期降水变化规律研究

Study on Variation Law of Precipitation in Flood Season in the Qinhe River Basin

利用沁河流域18个雨量站1971~2008年共38a汛期逐日降水资料,分别采用滑动平均法、累计距平、信噪比及小波分析等方法,研究了降水的趋势性及周期性变化。结果表明,38a来汛期降水量以7.89 mm/10a速率呈小幅的下降趋势;汛期降水不存在突变现象;年降水存在着27a、22a、6a及9a的主周期变化,27a周期振荡最为强烈。经预测,沁河流域在2008年后的一段时期内可能处于一个降水偏少期。

Based on daily precipitation in flood season dataset of 18 stations in the Qinhe River basin during 1971-2008, the trend and periodicity variation of precipitation in flood season were analyzed by using meth- ods of moving average, accumulative anomaly, ratio of signal to noise and wavelet analysis. The main results are as follows: the precipitation in flood season declined at a speed of 7.89 mm/10ain recent 38 years, but changes in amplitude are not significant;the precipitation in flood season doesn’t exist mutation phenomenon;the annual precipitation has 27, 22, 6 and 9 years periods, and the oscillation in 27 years were the most in- tense. The study forecast that the annual average precipitation in the Qinhe River basin maybe in the dry pe- riod after 2008.